通讯机构：
[Zhou, N ] H;Hunan Agr Univ, Hunan Engn Res Ctr Biochar, Changsha 410128, Peoples R China.;Hunan Agr Univ, Coll Chem & Mat Sci, Changsha 410128, Peoples R China.
摘要：
Transition-metal-catalyzed reactive oxygen species (ROS) play an important role in existing bactericidal systems, but there are some problems, such as poor stability, ease of dissolution, and difficulty in reusing. To address the issue of stability, we have developed a sufficient electron-donating (SED) system. In the presence of the two most active transition metals with multiple valences, several as-formed redox pairs can provide sufficient electrons, and then effectively trigger the reduction of H2O/O-2 to produce O-1(2), <middle dot>OH and <middle dot>O-2(-) without any assistance from extra energy or other active oxidants. Consequently, the SED system showed 100% removal efficiency for Escherichia coli in 2 h, and also showed remarkable stability and reusability with 85% inactivation after 11 repetitions. It is worth noting that <middle dot>OH and O-1(2) play a major role in the bactericidal process. While <middle dot>O-2(-) mainly plays a role in promoting the formation of O-1(2) and <middle dot>OH.
摘要：
Marginal lands, such as those with saline soils, have potential as alternative resources for cultivating dedicated biomass crops used in the production of renewable energy and chemicals. Optimum utilization of marginal lands can not only alleviate the competition for arable land use with primary food crops, but also contribute to bioenergy products and soil improvement. Miscanthus sacchariflorus and M. lutarioriparius are prominent perennial plants suitable for sustainable bioenergy production in saline soils. However, their responses to salt stress remain largely unexplored. In this study, we utilized 318 genotypes of M. sacchariflorus and M. lutarioriparius to assess their salt tolerance levels under 150 mM NaCl using 14 traits, and subsequently established a mini-core elite collection for salt tolerance. Our results revealed substantial variation in salt tolerance among the evaluated genotypes. Salt-tolerant genotypes exhibited significantly lower Na+ content, and K+ content was positively correlated with Na+ content. Interestingly, a few genotypes with higher Na+ levels in shoots showed improved shoot growth characteristics. This observation suggests that M. sacchariflorus and M. lutarioriparius adapt to salt stress by regulating ion homeostasis, primarily through enhanced K+ uptake, shoot Na+ exclusion, and Na+ sequestration in shoot vacuoles. To evaluate salt tolerance comprehensively, we developed an assessment value (D value) based on the membership function values of the 14 traits. We identified three highly salt-tolerant, 50 salt-tolerant, 127 moderately salt-tolerant, 117 salt-sensitive, and 21 highly salt-sensitive genotypes at the seedling stage by employing the D value. A mathematical evaluation model for salt tolerance was established for M. sacchariflorus and M. lutarioriparius at the seedling stage. Notably, the mini-core collection containing 64 genotypes developed using the Core Hunter algorithm effectively represented the overall variability of the entire collection. This mini-core collection serves as a valuable gene pool for future in-depth investigations of salt tolerance mechanisms in Miscanthus.
作者机构：
[Chen, Yinke; Peng, Yan; Teng, Zhenning; Duan, Meijuan; Ye, Nenghui; Qin, Zhonge; Liu, Bohan; Yu, Huihui; Ye, NH; Meng, Shuan; Lv, Jiahan; Duan, MJ] Hunan Agr Univ, Coll Agron, Hunan Prov Key Lab Rice Stress Biol, Changsha 410128, Peoples R China.;[Teng, Zhenning; Zhang, Jianhua; Yu, Huihui] Chinese Univ Hong Kong, Sch Life Sci, Hong Kong 999077, Peoples R China.;[Teng, Zhenning; Zhang, Jianhua; Yu, Huihui] Chinese Univ Hong Kong, State Key Lab Agrobiotechnol, Hong Kong 999077, Peoples R China.;[He, YC; He, Yuchi] Hubei Univ, Sch Life Sci, State Key Lab Biocatalysis & Enzyme Engn, Wuhan 430000, Peoples R China.;[Zhang, Jianhua; Ye, Nenghui; Ye, NH] Hong Kong Baptist Univ, Dept Biol, Hong Kong 999077, Peoples R China.
通讯机构：
[He, YC ; Zhang, JH; Ye, NH ; Duan, MJ] H;[Zhang, JH ] C;Hunan Agr Univ, Coll Agron, Hunan Prov Key Lab Rice Stress Biol, Changsha 410128, Peoples R China.;Chinese Univ Hong Kong, Sch Life Sci, Hong Kong 999077, Peoples R China.;Chinese Univ Hong Kong, State Key Lab Agrobiotechnol, Hong Kong 999077, Peoples R China.
摘要：
Low-temperature germination (LTG) is an important agronomic trait for direct-seeding cultivation of rice (Oryza sativa). Both OsMYB30 and OsTPP1 regulate the cold stress response in rice, but the function of OsMYB30 and OsTPP1 in regulating LTG and the underlying molecular mechanism remains unknown. Employing transcriptomics and functional studies revealed a sugar signaling pathway that regulates seed germination in response to low temperature (LT). Expression of OsMYB30 and OsTPP1 was induced by LT during seed germination, and overexpressing either OsMYB30 or OsTPP1 delayed seed germination and increased sensitivity to LT during seed germination. Transcriptomics and qPCR revealed that expression of OsTPP1 was upregulated in OsMYB30-overexpressing lines but downregulated in OsMYB30-knockout lines. In vitro and in vivo experiments revealed that OsMYB30 bound to the promoter of OsTPP1 and regulated the abundance of OsTPP1 transcripts. Overaccumulation of trehalose (Tre) was found in both OsMYB30- and OsTPP1-overexpressing lines, resulting in inhibition of alpha-amylase 1a (OsAMY1a) gene during seed germination. Both LT and exogenous Tre treatments suppressed the expression of OsAMY1a, and the osamy1a mutant was not sensitive to exogenous Tre during seed germination. Overall, we concluded that OsMYB30 expression was induced by LT to activate the expression of OsTPP1 and increase Tre content, which thus inhibited alpha-amylase activity and seed germination. This study identified a phytohormone-independent pathway that integrates environmental cues with internal factors to control seed germination. Low temperature increases the abundance of a transcription factor, which activates the biosynthesis of trehalose and consequently inhibits seed germination by impeding alpha-amylase activity in rice.
关键词：
Low nitrogen;Photosynthetic -nitrogen use efficiency;Brassica napus L
摘要：
The photosynthetic -nitrogen use efficiency (PNUE) of Brassica napus L. is reported to increase under low nitrogen (N) condition. However, the underlying physiological mechanisms are unclear. In this study, the physiological mechanisms underlying increase in the photosynthetic -nitrogen use efficiency of Brassica napus L. under lownitrogen condition were investigated by assessing the changes in plant architecture, light reception, nitrogen allocation, and leaf tissue structure. The plants exhibited dwarf, upright, and compact phenotype under lownitrogen condition. Although the total photons received by plants decreased, the average photosynthetic photon flux density remained unchanged. The nitrogen photon reception efficiency (NPRE, calculated as total photons/N accumulation in leaves) was significantly increased by 76.61%-100.63%. The proportion of nitrogen allocated for photosynthesis was increased by 22.06%-38.86%. Moreover, although the leaf thickness remained unchanged, the epidermal thickness increased, and the spongy tissues became thinner. The density of mesophyll cells and chloroplasts significantly increased. Low -nitrogen condition significantly decreased the resistance to CO2 transport and significantly increased stomatal conductance (gs), intercellular carbon dioxide concentration (Ci), mesophyll conductance (gm), and CO2 concentration in chloroplasts (Cc). Correlation analysis revealed that light reception, nitrogen allocation in the leaves, and leaf tissue structure were significantly correlated with PNUE. Random forest analysis revealed that nitrogen photon reception efficiency and storage nitrogen were the primary factors positively and negatively impacting photosynthetic -nitrogen use efficiency, respectively. This study enhanced the understanding of the physiological mechanism of increased PNUE of B. napus under lownitrogen condition.
摘要：
Cadmium (Cd) is a highly toxic heavy metal that can be readily absorbed by plants and enriched in human body. Rice (Oryza sativa L.) yield and grain quality are affected by excessive Cd in the soil. Therefore, understanding the mechanisms of Cd absorption, accumulation and detoxification in the root apex is crucial for developing low-Cd rice cultivars. After Cd treatment, Cd concentration in rice root tips (RT) was 1.4 times higher than that in basal roots (BR). To uncover the distinct molecular responses to Cd toxicity, we conducted transcriptomic, proteomic, and metabolomic analyses on the two root sections. The results revealed that the RT exhibited 1.2-2.0 fold higher transcript or protein abundance of several Cd-related transporters than the BR, including Nramp1, Nramp5, IRT1, and HMA3, thereby contributing to more Cd accumulation in the RT. Furthermore, multi-omics analysis unveiled that the RT had enhanced activity in 'phenylpropanoid metabolism', 'AsA-GSH cycle' and 'tryptophan metabolism', conferring the stronger antioxidant system. While the BR showed higher activation in 'cell wall remodeling' and 'terpenoid biosynthesis'. This comprehensive study provides insights into the regulatory network of genes, proteins and metabolites involved in the differential responses to Cd toxicity between rice root tips and mature zones.
摘要：
Chilling is a major abiotic stress affecting rice growth, development and geographical distribution. Plant vacuolar processing enzymes (VPEs) contribute to the seed storage protein processing and mediate the programmed cell death by abiotic and biotic stresses. However, little is known about the roles of plant VPEs in cold stress responses and tolerance regulation. Here, we found that OsVPE2 was a chilling-responsive gene. The early-indica rice variety Xiangzaoxian31 overexpressing OsVPE2 was more sensitive to chilling stress, whereas the OsVPE2-knockout mutants generated by the CRISPR-Cas9 technology exhibited significantly enhanced chilling tolerance at the seedling stage without causing yield loss. Deficiency of OsVPE2 reduces relative electrolyte leakage, accumulation of toxic compounds such as reactive oxygen species and malondialdehyde, and promotes antioxidant enzyme activities under chilling stress conditions. It was indicated that OsVPE2 mediated the disintegration of vacuoles under chilling stress, accompanied by the entry of swollen mitochondria into vacuoles. OsVPE2 suppressed the expression of genes that have a positive regulatory role in antioxidant process. Moreover, haplotype analysis suggested that the natural variation in the OsVPE2 non-coding region may endow OsVPE2 with different expression levels, thereby probably conferring differences in cold tolerance between japonica and indica sub-population. Our results thus reveal a new biological function of the VPE family in regulating cold resistance, and suggest that the gene editing or natural variations of OsVPE2 can be used to create cold tolerant rice varieties with stable yield.
摘要：
Lignin and cellulose are two essential elements of plant secondary cell walls that shape the mechanical characteristics of the culm to prevent lodging. However, how the regulation of the lignin and cellulose composition is combined to achieve optimal mechanical characteristics is unclear. Here, we show that increasing OsTCP19 expression in rice coordinately repressed lignin biosynthesis and promoted cellulose biosynthesis, resulting in enhanced lodging resistance. In contrast, repression of OsTCP19 coordinately promoted lignin biosynthesis and inhibited cellulose biosynthesis, leading to greater susceptibility to lodging. We found that OsTCP19 binds to the promoters of both MYB108 and MYB103L to increase their expression, with the former being responsible for repressing lignin biosynthesis and the latter for promoting cellulose biosynthesis. Moreover, up-regulation of OsTCP19 in fibers improved grain yield and lodging resistance. Thus, our results identify the OsTCP19-OsMYB108/OsMYB103L module as a key regulator of lignin and cellulose production in rice, and open up the possibility for precisely manipulating lignin-cellulose composition to improve culm mechanical properties for lodging resistance.
摘要：
Maize (Zea mays) cultivation is strongly affected by both abiotic and biotic stress, leading to reduced growth and productivity. It has recently become clear that regulators of plant stress responses, including the phytohormones abscisic acid (ABA), ethylene (ET), and jasmonic acid (JA), together with reactive oxygen species (ROS), shape plant growth and development. Beyond their well established functions in stress responses, these molecules play crucial roles in balancing growth and defense, which must be finely tuned to achieve high yields in crops while maintaining some level of defense. In this review, we provide an in-depth analysis of recent research on the developmental functions of stress regulators, focusing specifically on maize. By unraveling the contributions of these regulators to maize development, we present new avenues for enhancing maize cultivation and growth while highlighting the potential risks associated with manipulating stress regulators to enhance grain yields in the face of environmental challenges.
关键词：
Microbial anabolism;Necromass formation;Soil organic carbon;Paddy and upland soils;Climate zones
摘要：
Well -drained upland soils generally have stronger microbial catabolism during organic C transformation than water-logged paddy soils. However, the intensity of microbial anabolism and necromass formation processes in these contrasting agricultural soils is unclear. To quantify these processes, 40 pairs of adjacent upland and paddy soils collected from four climates (mid -temperate, warm temperate, subtropics, and tropics) across eastern China were incubated with 13C -labeled root exudates under simulated field water conditions for 50 days. Upland soil collected from warm temperate exhibited a higher 13C incorporation into living microbial biomass than other climates. In contrast, the lowest newly formed necromass was detected due to the inhibition of fungal anabolism under the high pH condition. Paddy soils collected from cooler climates (mid -temperate and warm temperate) exhibited faster microbial biomass growth than those from warmer climates (subtropics and tropics). Still an opposite trend was observed for microbial necromass accumulation, possibly because of the faster turnover rate of microbial biomass induced by the high N availability in warmer climates. Regardless of climates, 13C incorporated into living microbial biomass (phospholipid fatty acids) was 1.4-2.6 times higher in upland than paddy soils, resulting in 1.8-3.9 times greater accumulation of newly -formed microbial necromass in the former. This was mainly caused by the stronger fungal anabolism (2.5-5.6 times higher) due to the oxygen -sufficient condition of upland soil. Our findings highlighted the weaker accumulation but stronger stability of organic C stored in upland soils because of the greater microbial catabolism and anabolism during organic C transformation.
作者机构：
[Qiao, Hang; Duan, Xun; Ma, Chong] Chinese Acad Sci, Key Lab Agroecol Proc Subtrop Reg, Inst Subtrop Agr, Changsha 410125, Peoples R China.;[Rui, Yichao] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.;[Xia, Yinhang] Purdue Univ, Dept Agron, W Lafayette, IN 47907 USA.;[Hu, Yajun] Hunan Agr Univ, Coll Resources, Changsha 410128, Peoples R China.;[Chen, Xiangbi] Hunan Agr Univ, Coll Agron, Changsha 410125, Peoples R China.
通讯机构：
[Chen, XB ] C;Chinese Acad Sci, Inst Subtrop Agr, Mapoling Changsha City 410125, Hunan, Peoples R China.
关键词：
Microbial anabolism;Microbial catabolism;C use efficiency;Soil organic C;Paddy and upland soils;Climate zones
摘要：
Regularly flooded rice paddies usually show greater soil organic C and microbial-derived C contents than adjacent upland counterparts, but the soil microbial physiological traits under these two different land uses spanning regions remain unclear. Here, we collected 40 pairs of adjacent paddy and upland soils from four different climates (mid temperate, warm temperate, subtropics, and tropics) across eastern China to determine the microbial growth, respiration, and C use efficiency using the 18O-H2O incubation method. Upland soils from warmer climates exhibited lower microbial growth but higher respiration normalized to microbial biomass C (qGrowth and qRespiration, respectively) than those from cooler climates, since the lower soil pH and higher clay content in warmer climates induced a shift from microbial growth to respiration. Whereas, paddy soils from warmer climates had consistently lower qGrowth and qRespiration than cooler climates, probably due to the long term water-logged condition decreased the sensitivity of microbial metabolism in response to lower pH. Paddy soils had higher qGrowth, but lower qRespiration than upland soils, resulting in a greater C use efficiency regardless of climate zones. The difference in microbial C use efficiency between paddy and upland soils was positively correlated to their difference in soil organic C content. From the perspective of microbial C metabolism, the greater organic C accumulation in paddy than that in upland soils is attributed to the weaker microbial uptake of organic C and stronger microbial anabolism under the water-logged condition.
摘要：
Soil nutrient transformation and the microbial metabolism are primarily regulated by soil microorganisms, including fungi and bacteria, which exhibit distinct growth patterns, energy substrate utilization, and survival strategies. Despite their significance, our understanding of the key microorganisms governing the soil microbial metabolism and multifunctionality in subtropical woodlands remains limited. To address this knowledge gap, we conducted a large-scale investigation and assessment of the soil microbial metabolic limitation and soil multifunctionality in Camellia oleifera Abel and Pinus massoniana Lamb. woodlands in subtropical China. Our results reveal that the microbial phosphorus limitation was more severe in C. oleifera compared to P. massoniana woodlands. Nonetheless, the pattern of carbon metabolic limitation for microbes and soil multifunctionality was similar in both types of woodland. Specifically, the microbial carbon limitation was positively associated with both bacterial and fungal richness, while the microbial phosphorus limitation was significantly correlated with fungi including the richness and community structure in the P. massoniana woodland. By contrast, we did not observe significant correlations between microbial metabolic limitation indices and microbial parameters in C. oleifera woodlands. Regarding soil multifunctionality, the results reveal a strong positive correlation between the soil multifunctionality and fungal community in both P. massoniana and C. oleifera woodlands. Furthermore, our structural equation modeling revealed that the soil fungal community, rather than the bacterial community, had a significant effect on the microbial metabolic limitation and soil multifunctionality. Overall, our study provides profound insights into the relative importance of bacterial and fungal communities in shaping the soil microbial metabolic limitation and soil multifunctionality in subtropical woodlands. The findings of our study have important implications for the management and conservation of subtropical woodlands.
摘要：
The color of the seed coat has great diversity and is regarded as a biomarker of metabolic variations. Here we isolated a soybean variant (BLK) from a population of recombinant inbred lines with a black seed coat, while its sibling plants have yellow seed coats (YL). The BLK and YL plants showed no obvious differences in vegetative growth and seed weight. However, the BLK seeds had higher anthocyanins and flavonoids level and showed tolerance to various abiotic stresses including herbicide, oxidation, salt, and alkalinity during germination. Integrated metabolomic and transcriptomic analyses revealed that the upregulation of biosynthetic genes probably contributed to the overaccumulation of flavonoids in BLK seeds. The transient expression of those biosynthetic genes in soybean root hairs increased the levels of total flavonoids or anthocyanins. Our study revealed the molecular basis of flavonoid accumulation in soybean seeds, leveraging genetic engineering for both nutritious and stress-tolerant soybean germplasm.
摘要：
The germination of seeds is a prerequisite for crop production. Protrusion is important for seed germination, and visible radicle protrusion through seed covering layers is the second phase of the process of seed germination. Analyzing the mechanism of protrusion is important for the cultivation of rice varieties. In this study, 302 microcore germplasm populations were used for the GWAS of the protrusion percentage (PP). The frequency distribution of the PP at 48 h and 72 h is continuous, and six PP-associated QTLs were identified, but only qPP2 was detected repeatedly two times. The candidate gene analysis showed that LOC_Os02g57530 (ETR3), LOC_Os01g57610 (GH3.1) and LOC_Os04g0425 (CTB2) were the candidate genes for qPP2, qPP1 and qPP4, respectively. The haplotype (Hap) analysis revealed that Hap1 of ETR3, Hap1 and 3 of GH3.1 and Hap2 and 5 of CTB2 are elite alleles for the PP. Further validation of the germination phenotype of these candidate genes showed that Hap1 of ETR3 is a favorable allele for the germination percentage; Hap3 of GH3.1 is an elite allele for seed germination; and Hap5 of CTB2 is an elite allele for the PP, the germination percentage and the vigor index. The results of this study identified three putative candidate genes that provide valuable information for understanding the genetic control of seed protrusion in rice.
摘要：
Tocopherol is an important lipid-soluble antioxidant beneficial for both human health and plant growth. Here, we fine mapped a major QTL-qVE1 affecting γ-tocopherol content in maize kernel, positionally cloned and confirmed the underlying gene ZmPORB1 (por1), as a protochlorophyllide oxidoreductase. A 13.7 kb insertion reduced the tocopherol and chlorophyll content, and the photosynthetic activity by repressing ZmPORB1 expression in embryos of NIL-K22, but did not affect the levels of the tocopherol precursors HGA (homogentisic acid) and PMP (phytyl monophosphate). Furthermore, ZmPORB1 is inducible by low oxygen and light, thereby involved in the hypoxia response in developing embryos. Concurrent with natural hypoxia in embryos, the redox state has been changed with NO increasing and H(2)O(2) decreasing, which lowered γ-tocopherol content via scavenging reactive nitrogen species. In conclusion, we proposed that the lower light-harvesting chlorophyll content weakened embryo photosynthesis, leading to fewer oxygen supplies and consequently diverse hypoxic responses including an elevated γ-tocopherol consumption. Our findings shed light on the mechanism for fine-tuning endogenous oxygen concentration in the maize embryo through a novel feedback pathway involving the light and low oxygen regulation of ZmPORB1 expression and chlorophyll content.
摘要：
The glutathione S‐transferase gene OsGSTU26 and the amino acid transporter gene OsAAT30, the major genes for heterosis in salinity tolerance, act in an overdominant fashion in hybrid rice CY1000. OsWRKY72 regulates reactive oxygen species scavenging under salt stress by repressing their expression, thus mediating heterobeltiosis for salinity tolerance. ABSTRACT Hybrid rice (Oryza sativa) generally outperforms its inbred parents in yield and stress tolerance, a phenomenon termed heterosis, but the underlying mechanism is not completely understood. Here, we combined transcriptome, proteome, physiological, and heterosis analyses to examine the salt response of super hybrid rice Chaoyou1000 (CY1000). In addition to surpassing the mean values for its two parents (mid‐parent heterosis), CY1000 exhibited a higher reactive oxygen species scavenging ability than both its parents (over‐parent heterosis or heterobeltiosis). Nonadditive expression and allele‐specific gene expression assays showed that the glutathione S‐transferase gene OsGSTU26 and the amino acid transporter gene OsAAT30 may have major roles in heterosis for salt tolerance, acting in an overdominant fashion in CY1000. Furthermore, we identified OsWRKY72 as a common transcription factor that binds and regulates OsGSTU26 and OsAAT30. The salt‐sensitive phenotypes were associated with the OsWRKY72paternal genotype or the OsAAT30maternal genotype in core rice germplasm varieties. OsWRKY72paternal specifically repressed the expression of OsGSTU26 under salt stress, leading to salinity sensitivity, while OsWRKY72maternal specifically repressed OsAAT30, resulting in salinity tolerance. These results suggest that the OsWRKY72–OsAAT30/OsGSTU26 module may play an important role in heterosis for salt tolerance in an overdominant fashion in CY1000 hybrid rice, providing valuable clues to elucidate the mechanism of heterosis for salinity tolerance in hybrid rice.
关键词：
functional-structure plant modeling (FSPM);mechanized planting;micro-light climate;Chinese solar greenhouse;GroIMP
摘要：
Understanding the spatial heterogeneity of light and photosynthesis distribution within a canopy is crucial for optimizing plant growth and yield, especially in the context of greenhouse structures. In previous studies, we developed a 3D functional-structural plant model (FSPM) of the Chinese solar greenhouse (CSG) and tomato plants, in which the greenhouse was reconstructed as a 3D mockup and implemented in the virtual scene. This model, which accounts for various environmental factors, allows for precise calculations of radiation, temperature, and photosynthesis at the organ level. This study focuses on elucidating optimal canopy configurations for mechanized planting in greenhouses, building upon the commonly used north-south (N-S) orientation by exploring the east-west (E-W) orientation. Investigating sixteen scenarios with varying furrow distance (1 m, 1.2 m, 1.4 m, 1.6 m) and row spacing (0.3 m, 0.4 m, 0.5 m, 0.6 m), corresponding to 16 treatments of plant spacing, four planting patterns (homogeneous row, double row, staggered row, incremental row) and two orientations were investigated. The results show that in Shenyang city, an E-W orientation with the path width = 0.5 (furrow distance + row distance) = 0.8 m (homogeneous row), and a plant distance of 0.32 m, is the optimal solution for mechanized planting at a density of 39,000 plants/ha. Our findings reveal a nuanced understanding of how altering planting configurations impacts the light environment and photosynthesis rate within solar greenhouses. Looking forward, these insights not only contribute to the field of CSG mechanized planting, but also provide a basis for enhanced CSG planting management. Future research could further explore the broader implications of these optimized configurations in diverse geographic and climatic conditions.
摘要：
Background and aims Sustainable rice production is crucial for addressing food security and mitigating climate change. Optimizing irrigation techniques that strike a balance between rice yields and carbon sequestration has gained significant attention. Intermittent irrigation has been considered a compromise between these two factors. However, uncertainties persist regarding the impact of intermittent irrigation on ratoon rice cultivation. Methods To address this, we conducted field experiments to investigate the influence of intermittent irrigation on rice yield and CO2/CH4 emissions in ratoon rice systems at Qianshanhong Farm, located in Yiyang, Hunan Province, China. We utilized a portable greenhouse gas analyzer from Los Gatos Research (LGR) alongside the closed chamber method to measure gas fluxes accurately. The experiments were conducted on Huanghuazhan rice cultivar, with each plot encompassing 45 m(2). The experiments included intermittent irrigation treatment and conventional flooded irrigation treatment as a control. Results The study found that the ecosystem respiration (ER), heterotrophic soil respiration (HR), Gross primary productivity (GPP), Plant autotrophic respiration (PR), and total accumulated CH4 emissions from the ecosystem (E-CH4) of ratoon rice decreased owing to intermittent irrigation. Intermittent irrigation increased rice yield and biomass by 6.04% and 3.88%, respectively, but the differences were not significant (P > 0.05). However, ratoon rice exhibited increased Net ecosystem photosynthetic exchange (NEE), Net primary productivity (NPP), and Net ecosystem productivity (NEP) after intermittent irrigation. Furthermore, there was a 57.78% reduction in the global warming potential (GWP) of the sum CO2-eq of CO2 and CH4 flux throughout the intermittent irrigation period. Conclusions Intermittent irrigation of ratoon rice decreased C release from the rice ecosystem while maintaining yields, therefore this approach is recommended.
摘要：
In order to explore the effect of fertilization patterns on the growth of rapeseed seedlings under waterlogging stress, three fertilization patterns (conventional fertilization, supplemental organic fertilization, and supplemental microbial fertilization) were set up using the variety Xiangyou 708 as the material, and waterlogging treatment was carried out during the seedling stage of rapeseed. The effects of fertilization patterns on the growth of rapeseed seedlings and rhizosphere microorganisms under waterlogging stress were investigated. The results showed that all three fertilization patterns exhibited that waterlogging stress inhibited the growth of rapeseed seedlings, inhibited root activity, and changed the structure of rhizosphere bacterial community structure. However, supplemental organic and microbial fertilization better promoted the growth of rapeseed seedlings, reduced the impact of waterlogging stress on the growth of rapeseed seedlings, and accelerated the recovery of rapeseed seedlings after waterlogging stress. Under normal water supply, supplemental organic fertilization enriched P_Bacteroidota, P_Actinobacteriota, P_Chloroflexi, and G_Flavisolibacter in the rhizosphere soil of rapeseed, while supplemental microbial fertilization enriched P_Bacteroidota and G_Flavisolibacter in the rhizosphere soil of rapeseed. After 7 days of waterlogging treatment, supplemental organic fertilization enriched P_Verrucomicrobiota in the rhizosphere soil of rapeseed, while supplemental microbial fertilization enriched P_Actinobacteriota, G_SC-I-84, and G_Ellin6067 in the rhizosphere soil of rapeseed. The enrichment of these bacteria may be related to the growth promotion and waterlogging tolerance of rapeseed. This study provides evidence that microbial and organic fertilizer can promote the growth of rapeseed and enhance its waterlogging tolerance, as well as evidence that some rhizosphere microorganisms have a potential role in promoting the growth and waterlogging tolerance of rapeseed.
摘要：
The cadmium (Cd) accumulates in birnessite as it forms on the surface of paddy crusts (PC). The stability of Cd-containing birnessite is influenced by environmental factors, and destabilized birnessite releases dissolved Cd. We report the effects of pH, oxalic acid, and light on the dissolution of Cd-containing birnessite. We found that at pH 4.0, with light and 0.20 mol/L oxalic acid, the ratio of dissolved Cd and manganese (Mn) peaked after 24 h at 2978.0 mu g/g and 326.8 mg/g, respectively. The three environmental factors affected the dissolution of Cd-containing birnessite in the following order: pH > oxalic acid > light. During dissolution process, Cd and Mn did not dissolve simultaneously, and the dissolved Cd/Mn ratio in the solution was significantly lower than that of the pristine mineral (33.5 x 10(-3)). Compared with Mn, Cd dissolution was inhibited by strong acidity (pH 4.0-5.0), and the dissolved Cd/Mn ratio was 5-10 x 10(-3). Mild acidity (pH 6.0) was weakly inhibitory, with a Cd/Mn ratio of 6-15 x 10(-3). In an alkaline (pH 8.0) oxalate environment, light illumination inhibited Cd dissolution, and the Cd/Mn ratio decreased over time due to the stability of the products formed by oxalate and carbonate, with Cd being more stable than those formed by Mn. Our findings would provide insights into the migration and transformation of PC-associated Cd in paddy fields.
