摘要：
Phosphorus-solubilizing bacteria are widely studied for their ability to immobilize heavy metals and promote plant growth. However, previous studies have been focused on the effects of phosphate-solubilizing bacteria on phosphorus release and heavy metal immobilization, and there is a lack of research on the effects of phosphatesolubilizing bacteria on rhizosphere soil bacterial communities and metabolites. In this study, the effects of Klebsiella sp. M2 on wheat rhizosphere microbiome and metabolism were investigated as well as the impact of these changes on wheat absorption of Cd. The results showed that under Cd stress, strain M2 reduced (77.54 %) the content of Cd in culture medium and secreted metabolites involved in plant growth promotion, Cd resistance, and phosphorus solubilization. A pot experiment showed that compared with the control, strain M2 increased (14.3 %-35.9 %) the dry weight and reduced (33.3 %-66.7 %) the content of Cd in wheat grains, straw, and roots. Strain M2 increased the exchangeable Ca, Ca2-P and Fe-P contents, soil pH, and alkaline phosphatase activity and decreased the acid-extractable Cd content in rhizosphere soil. The increase in Ca concentration had a significant promoting effect on the pH in rhizosphere soil. Moreover, the relative abundances of key bacteria such as Ramlibacter, Microvirga, Pseudarthrobacter, Massilia, Streptomyces, and Paenibacillus increased. Additionally, strain M2 increased the contents of some substances in rhizosphere soil that play an important role in immobilizing Cd and solubilizing phosphorus as well as improving wheat tolerance to Cd. The results showed that inoculation with an exogenous phosphate-solubilizing bacterial strain can result in the activation of key functional bacteria and the regulation of metabolite production in wheat rhizosphere soil to immobilize heavy metals, which has broad potential in the remediation of wheat fields with high heavy metal levels.
摘要：
The application of phosphorus-solubilizing bacteria is an effective method for increasing the available phosphorus content and inhibiting wheat uptake of heavy metals. However, further research is needed on the mechanism by which phosphorus-solubilizing bacteria inhibit cadmium (Cd) uptake in wheat roots and its impact on the expression of root-related genes. Here, the effects of strain Klebsiella aerogenes M2 on Cd absorption in wheat and the expression of root-related Cd detoxification and immobilization genes were determined. Compared with the control, strain M2 reduced (64.1-64.6%) Cd uptake by wheat roots. Cd fluorescence staining revealed that strain M2 blocked the entry of exogenous Cd into the root interior and enhanced the immobilization of Cd by cell walls. Forty-seven genes related to Cd detoxification, including genes encoding peroxidase, chalcone synthase, and naringenin 3-dioxygenase, were upregulated in the Cd+M2 treatment. Strain M2 enhanced the Cd resistance and detoxification activity of wheat roots through the regulation of flavonoid biosynthesis and antioxidant enzyme activity. Moreover, strain M2 regulated the expression of genes related to phenylalanine metabolism and the MAPK signaling pathway to enhance Cd immobilization in roots. These results provide a theoretical basis for the use of phosphorus-solubilizing bacteria to remediate Cd-contaminated fields and reduce Cd uptake in wheat.
摘要：
Undesirable population canopy structure and light-energy utilization efficiency are the most important problems faced in the process of increasing rapeseed yield from dense planting. The pod canopy staggered-layer cultivation mode used in this study combines the advantages of intercropping, mixed cropping, and dense planting. Specifically, within the premise of planting short-stalked rapeseed at high density, a certain quantity of tall-stalked rapeseed is randomly and uniformly planted in the inter-rows of the short-stalked rapeseed population. By layering the canopies of talkand short-stalked rapeseed, this mode fully utilizes land resources and upper-space light energy, ultimately achieving the goal of stable yield increase. In a two-year field trial, the control was a monoculture of both GX-23gao (tall-stalked rapeseed) and 77ai (short-stalked rapeseed) at a high density of 2.78x105 plants ha- 1; The treatment was to plant a different quantity of GX-23gao in the same 77ai population as the control. Results showed that when the planting quantity of GX-23gao reached 5 %, 10 %, and 20 % of the planting quantity of 77ai, the light transmittance of the canopy did not significantly decrease, and the extinction coefficient of the canopy remained at a relatively low level. The light-energy requirement of 77ai was not significantly affected under the shading conditions of the GX-23gao canopy. Furthermore, due to the staggeredlayer cultivation mode, GX-23gao received more sufficient light compared to monoculture, leading to enhanced photosynthesis. As a result, the total leaf area index and total population photosynthetic rate of the rapeseed population were higher than those of the 77ai population in the control group, and the yield increased. Among them, when the number of GX-23gao planted reached 20 % of the number of 77ai planted, the yield per unit area increased significantly by 16.57 %. However, when the planting quantity of GX-23gao reached 30 % and 40 % of the planting quantity of 77ai, the shading effects of the GX-23gao canopy had a significant negative impact, affecting the light requirements of both 77ai and GX-23gao, resulting in low or even negative yield benefits. These findings suggest that when the planting quantity of tall-stalk rapeseed did not exceed 20 % of the planting quantity of short-stalk rapeseed, the pod canopy staggered-layer cultivation could effectively improve the canopy structure and the utilization of upper-space light resources, thereby stably increasing rapeseed yield. This research presents a new cultivation mode for increasing rapeseed yield.
通讯机构：
[Liu, ZQ ] ;South China Agr Univ, Coll Agr, Guangdong Prov Key Lab Plant Mol Breeding, Guangzhou 510642, Guangdong, Peoples R China.;South China Agr Univ, State Key Lab Conservat & Utilizat Subtrop Agrobio, Guangzhou 510642, Guangdong, Peoples R China.
摘要：
<jats:title>Abstract</jats:title><jats:p>Understanding the evolutionary forces in speciation is a central goal in evolutionary biology. Asian cultivated rice has two subspecies, <jats:italic>indica</jats:italic> and <jats:italic>japonica</jats:italic>, but the underlying mechanism of the partial reproductive isolation between them remains obscure. Here we show a presence-absence variation (PAV) at the <jats:italic>Se</jats:italic> locus functions as an <jats:italic>indica-japonica</jats:italic> reproductive barrier by causing hybrid sterility (HS) in <jats:italic>indica-japonica</jats:italic> crosses. The locus comprises two adjacent genes: <jats:italic>ORF3</jats:italic> encodes a sporophytic pollen killer, whereas <jats:italic>ORF4</jats:italic> protects pollen in a gametophytic manner. In F<jats:sub>1</jats:sub> of <jats:italic>indica-japonica</jats:italic> crosses, pollen with the <jats:italic>japonica</jats:italic> haplotype, which lacks the sequence containing the protective <jats:italic>ORF4</jats:italic>, is aborted due to the pollen-killing effect of <jats:italic>ORF3</jats:italic> from <jats:italic>indica</jats:italic>. Evolutionary analysis suggests <jats:italic>ORF3</jats:italic> is a gene associated with the Asian cultivated rice species complex, and the PAV has contributed to the reproductive isolation between the two subspecies of Asian cultivated rice. Our analyses provide perspectives on rice inter-subspecies post-zygotic isolation, and will promote efforts to overcome reproductive barriers in <jats:italic>indica-japonica</jats:italic> hybrid rice breeding.</jats:p>
作者机构：
[Ruan, Ying; Fei, Mingliang] Hunan Agr Univ, Key Lab Crop Epigenet Regulat & Dev Hunan Prov, Changsha 410128, Peoples R China.;[Hu, Jia; Jin, Yunkai; Sun, Chuanxin; Fei, Mingliang] Swedish Univ Agr Sci SLU, Uppsala BioCtr, Linnean Ctr Plant Biol, Dept Plant Biol, POB 7080, S-75007 Uppsala, Sweden.;[Ruan, Ying; Liu, Chunlin; Fei, Mingliang] Hunan Agr Univ, Coll Biosci & Biotechnol, Key Lab Educ Dept Hunan Prov Plant Genet & Mol Bi, Changsha 410128, Peoples R China.;[Andersson, Annica A. M.; Seisenbaeva, Gulaim; Dotsenko, Gleb; Andersson, Roger] Swedish Univ Agr Sci, Uppsala BioCtr, Dept Mol Sci, POB 7015, S-75007 Uppsala, Sweden.;[Liu, Chunlin] Hunan Agr Univ, Coll Agron, Changsha 410128, Peoples R China.
通讯机构：
[Ruan, Ying] K;[Sun, Chuanxin] D;Key Laboratory of Crop Epigenetic Regulation and Development in Hunan Province, Hunan Agricultural University, Changsha, China<&wdkj&>Key Laboratory of Education Department of Hunan Province On Plant Genetics and Molecular Biology, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, China<&wdkj&>Department of Plant Biology, Uppsala BioCenter, Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
摘要：
High fructan content in the grain of cereals is an important trait in agriculture such as environmental resilience and dietary fiber food production. To understand the mechanism in determining final grain fructan content and achieve high fructan cereal, a cross breeding strategy based on fructan synthesis and hydrolysis activities was set up and have achieved barley lines with 11.8% storage fructan in the harvested grain. Our study discovered that high activity of fructan hydrolysis at later grain developmental stage leads to the low fructan content in mature seeds, simultaneously increasing fructan synthesis at early stage and decreasing fructan hydrolysis at later stage through crossing breeding is an efficient way to elevate grain diet-fiber content. A good correlation between fructan and beta glucans was also discovered with obvious interest. Field trials showed that the achieved high fructan barley produced over seven folds higher fructan content than control barley and pull carbon-flux to fructan through decreasing fructan hydrolysis without disruption starch synthesis will probably not bring yield deficiency.
摘要：
SWN （Swinger）蛋白是多梳抑制复合体2 （polycomb repressive complex2, PRC2）结构的核心成分之一,为了研究SWN在拟南芥中耐盐胁迫方面的作用,我们分析了拟南芥突变体swn与野生型之间转录组水平的基因表达差异,高盐胁迫下的萌发实验,以及与盐胁迫响应基因RD20 （Responsive to desiccation 20）、SOS1 （Salt overly sensitive）和MAPK6 （Mitogen-activated protein kinase）的表达。结果显示,GO富集分析表达上调的基因,共富集到20个GO通路,其中响应盐胁迫通路（Respond to salt stress）富集程度较高;在高盐胁迫下,swn表现出比野生型更高的萌发率,幼苗生长情况也优于野生型;盐胁迫响应基因RD20、SOS1和MAPK6表达量也更高。本研究表明,swn突变体对盐的耐受性强于野生型,SWN基因在拟南芥抗盐过程中发挥负调控作用。
摘要：
BackgroundPolycomb group (PcG) proteins play important roles in animal and plant development and stress response. Polycomb repressive complex 1 (PRC1) and PRC2 are the key epigenetic regulators of gene expression, and are involved in almost all developmental stages. PRC1 catalyzes H2A monoubiquitination resulting in transcriptional silencing or activation. The PRC1 components in the green lineage were identified and evolution and conservation was analyzed by bioinformatics techniques. RING Finger Protein 1 (RING1), B lymphoma Mo-MLV insertion region 1 homolog (BMI1), Like Heterochromatin Protein 1 (LHP1) and Embryonic Flower 1 (EMF1) are the PRC1 core components and Vernalization 1 (VRN1), VP1/ABI3-Like 1/2/3 (VAL1/2/3), Alfin-like 1-7 (AL1-7), Inhibitor of growth 1/2 (ING1/2), and Early Bolting in Short Days (EBS) / Short Life (SHL) are the associated factors.ResultsEach PRC1 subunit possesses special domain organizations, such as RING and the ring finger and WD40-associated ubiquitin-like (RAWUL) domains for RING1 and BMI1, chromatin organization modifier (CHROMO) and chromo shadow (ChSh) domains for LHP1, one or two B3 DNA binding domain(s) for VRN1, B3 and zf-CW domains for VAL1/2/3, Alfin and Plant HomeoDomain (PHD) domains for AL1-7, ING and PHD domains for ING1/2, Bromoadjacent homology (BAT) and PHD domains for EBS/SHL. Six new motifs are uncovered in EMF1.The PRC1 core components RING1 and BMI1, and the associated factors VAL1/2/3, AL1-7, ING1/2, and EBS/SHL exist from alga to higher plants, whereas LHP1 only occurs in higher plants. EMF1 and VRN1 are present only in eudicots. PRC1 components undergo duplication in the plant evolution. Most of plants carry the homologous core component LHP1, the associated factor EMF1, and several homologs in RING1, BMI1, VRN1, AL1-7, ING1/2/3, and EBS/SHL. Cabbage, cotton, poplar, orange and maize often exhibit more gene copies than other species. Domain organization analysis shows that duplicated gene functions may be of diverse.ConclusionsThe PRC1 core components RING1 and BMI1, and the associated factors VAL1/2/3, AL1-7, ING1/2, and EBS/SHL originate from algae. The core component LHP1 is from moss and the associated factors EMF1 and VRN1 are from dicotyledon. PRC1 components are of functional redundancy and diversity in evolution.
摘要：
Sulfotransferases (SOTs; EC 2.8.2.-), which are widespread from prokaryotes to eukaryotes, constitute a multi-protein family that plays crucial roles in plant growth, development and stress adaptation. However, this family has not been systemically investigated in Brassica rapa. Here, a genome-wide systemic analysis of SOT genes in B. rapa subsp. pekinensis, a globally cultivated vegetable, were conducted. We identified 56 SOT genes from the whole B. rapa genome using Arabidopsis SOT sequences as queries and classified them into nine groups, rather than the eight groups of previous research. 56 B. rapa SOT genes (BraSOTs) were distributed on all 10 chromosomes except for chromosome 5. Of these, 27 BraSOTs were distributed in seven clusters on five chromosomes (ChrA01, ChrA02, Chr03, ChrA07, and Chr09). Among the BraSOT proteins, 48 had only one SOT_1 domain and 6 had two, while 2 had one SOT_3 domain. Additionally, 47 BraSOT proteins contained only known SOT domains. The remaining nine proteins, five in group-VIII and two in group-IX, contained additional transmembrane domains. Specific motif regions I and IV for 3'-phosphoadenosine 5'-phosphosulfate binding were found in 41 BraSOT proteins. Introns were present in only 18 BraSOT genes, and all seven BraSOT genes in groups VIII and IX had more than three introns. To identify crucial SOTs mediating the response to abiotic stress in B. rapa, expression changes in 56 BraSOT genes were determined by quantitative RT-PCR after drought, salinity, and ABA treatments, and some BraSOT genes were associated with NaCl, drought and ABA stress, e.g. Bra017370, Bra009300, Bra027880.
摘要：
Priming for better defense performance is an important strategy in acclimation to the ever-changing environment. In the present study, defense priming induced by sodium chloride at the seedling stage significantly increased the expression of defense gene VSP2, the content of total glucosinolates and the level of the reactive oxygen species in mature Arabidopsis thaliana plants after transferred into the stress-free environment. The previously primed plants could effectively resist the feeding of Spodoptera litura (Fabricius) larvae. Salt-priming enhanced defense of Arabidopsis plants in the absence of either MYC2 or AOS, which encodes a critical transcription factor in JA-signaling and an important enzyme in JA biosynthesis, respectively. Our results supported the JA-independent defense primed by sodium chloride, as well as the elevated ROS and glucosinolate level in primed plants. In addition, the feasibility of using mild salt-priming to improve crop performance in field was proposed.
