摘要：
<jats:sec><jats:title>Background</jats:title><jats:p>Brassinosteroids (BRs) are a class of naturally occurring steroidal phytohormones mediating a wide range of pivotal developmental and physiological functions throughout the plant’s life cycle. Therefore, it is of great significance to determine the content and the distribution of BRs in plants.Regretfully, although a large number of quantitative methods for BRs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) have been reported, the <jats:italic>in planta</jats:italic> distribution of BRs is still unclear because of their lower contents in plant tissues and the lack of effective ionizable groups in their chemical structures.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We stablished a novel analytical method of BRs based on C18 cartridge solid-phase extraction (SPE) purification, 4-(dimethylamino)-phenylboronic acid (DMAPBA) derivatization, and online valve-switching system coupled with ultra-high performance liquid chromatography-electro spray ionization-triple quadrupole mass spectrometry (UHPLC-ESI-MS/MS). This method has been used to quantify three structural types of BRs (epibrassinolide, epicastasterone, and 6-deoxo-24-epicastaster one) in different organs of <jats:italic>Brassica napus</jats:italic> L. (rapeseed).</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>We obtained the contents of three structural types of BRs in various organ tissues of rapeseed. The contents of three BRs in rapeseed flowers were the highest, followed by tender pods. The levels of three BRs all decreased during the maturation of the organs. We outlined the spatial distribution maps of three BRs in rapeseed based on these results, so as to understand the spatial distribution of BRs at the visual level.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Our results provided useful information for the precise <jats:italic>in situ</jats:italic> localization of BRs in plants and the metabolomic research of BRs in future work. The <jats:italic>in planta</jats:italic> spatial distribution of BRs at the visual level has been studied for the first time.</jats:p></jats:sec>
摘要：
Plant senescence is a highly coordinated process that is intricately regulated by numerous endogenous and environmental signals. The involvement of phytic acid in various cell signaling and plant processes has been recognized, but the specific roles of phytic acid metabolism in Arabidopsis leaf senescence remain unclear. Here, we demonstrate that in Arabidopsis thaliana the multiple inositol phosphate phosphatase (AtMINPP) gene, encoding an enzyme with phytase activity, plays a crucial role in regulating leaf senescence by coordinating the ethylene signal transduction pathway. Through overexpressing AtMINPP (AtMINPP-OE), we observed early leaf senescence and reduced chlorophyll contents. Conversely, a loss-of-function heterozygous mutant (atminpp/+) exhibited the opposite phenotype. Correspondingly, the expression of senescence-associated genes (SAGs) was significantly upregulated in AtMINPP-OE but markedly decreased in atminpp/+. Yeast one-hybrid and chromatin immunoprecipitation assays indicated that the EIN3 transcription factor directly binds to the promoter of AtMINPP. Genetic analysis further revealed that AtMINPP-OE could accelerate the senescence of ein3-1eil1-3 mutants. These findings elucidate the mechanism by which AtMINPP regulates ethylene-induced leaf senescence in Arabidopsis, providing insights into the genetic manipulation of leaf senescence and plant growth.
作者：
Hélène S. Robert;Marcus G. Heisler;Langtao Xiao;Benoit Landrein
期刊：
FRONTIERS IN PLANT SCIENCE,2023年14:1319859 ISSN：1664-462X
作者机构：
[Hélène S. Robert] Hormonal Crosstalk in Plant Development, Mendel Center for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University (CEITEC MU), Czechia;[Marcus G. Heisler] School of Life and Environmental Sciences, University of Sydney, Australia;[Langtao Xiao] College of Bioscience and Biotechnology, Hunan Agricultural University, China;[Benoit Landrein] Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon, CNRS, INRAE, INRIA, France
期刊：
Reproduction and Breeding,2023年3(1):17-25 ISSN：2667-0712
作者机构：
College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China;Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha, 410128, China;[Wei Li] Tea Research Institute, Hunan Academy of Agricultural Sciences, Changsha, 410125, China;[Zhoufei Luo; Xianxin Zhu; Hui Li; Yu Jian; Haiou Li; Chao Huang; Ruozhong Wang; Langtao Xiao] College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha, 410128, China
关键词：
Methyl jasmonate stereoisomer;Tea (Camellia sinensis L.);Air-assisted liquid-liquid microextraction;Enantioselective gas chromatography-tandem mass spectrum;Injury
摘要：
Different stereoisomers of phytohormones may have different roles in plants while the quantification for stereoisomers still remains a challenge. The chiral separation method for methyl jasmonate (MeJA) in tea (Camellia sinensis L.) was developed by air-assisted liquid-liquid microextraction (AALLME) with enantioselective gas chromatography-mass spectrometry (Es-GC-MS/MS). The Plackett-Burman factorial design was introduced to optimize the multiple parameters of AALLME. Sensitive Es-GC-MS/MS enabled the quantification of the MeJA stereoisomers, which were separated from each other with resolutions of 3.5, 2.7, and 2.5. The linearities were R2 > 0.9971, the limits of detection were 0.08–0.12 ng/mL, the limits of quantification (LOD) were 0.28–0.39 ng/mL, and the recovery range was 80.60–107.03%. The method was applied to analyze the MeJA stereoisomer profiles in tea plants after geometrid feeding and mechanical wounding. (+)-MeJA appeared to be the main bio-active monomer that responded to injury stress. (+)-MeJA similarly increased in tea shoots at only 30 s after geometrid attack or mechanical wounding. The proposed method is superior as air-assisted liquid-liquid microextraction could induce the loss of volatile MeJA in a much shorter time, compared to the conventional enrichment procedure. A novel assay protocol for relative quantification of MeJA stereoisomers in plants responding to different injuries was applied.
作者机构：
[Zhou, Chuanen; Wang, Hongfeng; Lu, Zhichao; Zhang, Jing; Xu, Yiteng; Han, Lu] Shandong Univ, Sch Life Sci, Key Lab Plant Dev & Environm Adaptat Biol, Minist Educ, Qingdao 266101, Peoples R China.;[Chai, Maofeng; Wang, Zeng-Yu] Qingdao Agr Univ, Grassland Agrihusb Res Ctr, Qingdao 266109, Peoples R China.;[Yang, Xianpeng] Shandong Normal Univ, Coll Life Sci, Jinan 250014, Peoples R China.;[Lu, Shiyou] Hubei Univ, Sch Life Sci, State Key Lab Biocatalysis & Enzyme Engn, Wuhan 430062, Peoples R China.;[Tong, Jianhua; Xiao, Langtao] Hunan Agr Univ, Hunan Prov Key Lab Phytohormones & Growth Dev, Hunan Prov Key Lab Crop Germplasm Innovat & Utiliz, Changsha 410128, Peoples R China.
通讯机构：
[Chuanen Zhou] T;The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University , Qingdao 266101 , China
摘要：
Outermost cell layer-specific biosynthesis of very long-chain fatty acids is critical for the cell membrane integrity, which is important for auxin-mediated compound leaf patterning in barrelclover. Plant cuticles are composed of hydrophobic cuticular waxes and cutin. Very long-chain fatty acids (VLCFAs) are components of epidermal waxes and the plasma membrane and are involved in organ morphogenesis. By screening a barrelclover (Medicago truncatula) mutant population tagged by the transposable element of tobacco (Nicotiana tabacum) cell type1 (Tnt1), we identified two types of mutants with unopened flower phenotypes, named unopened flower1 (uof1) and uof2. Both UOF1 and UOF2 encode enzymes that are involved in the biosynthesis of VLCFAs and cuticular wax. Comparative analysis of the mutants indicated that the mutation in UOF1, but not UOF2, leads to the increased number of leaflets in M. truncatula. UOF1 was specifically expressed in the outermost cell layer (L1) of the shoot apical meristem (SAM) and leaf primordia. The uof1 mutants displayed defects in VLCFA-mediated plasma membrane integrity, resulting in the disordered localization of the PIN-FORMED1 (PIN1) ortholog SMOOTH LEAF MARGIN1 (SLM1) in M. truncatula. Our work demonstrates that the UOF1-mediated biosynthesis of VLCFAs in L1 is critical for compound leaf patterning, which is associated with the polarization of the auxin efflux carrier in M. truncatula.
作者机构：
[Gaballah M.M.; Abu El-Ezz A.F.] Agricultural Research Center, Field Crops Research Institute, Rice Research and Training Center, Sakha, Kafr Elsheikh, Egypt;[Ghoneim A.M.] Agricultural Research Center (ARC), Field Crops Research Institute, Giza, Egypt;[Yang B.] Winall Thriving Seed Co., Ltd., Hefei, Anhui, China;[Xiao L.] Hunan Agricultural University, Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Changsha, China
通讯机构：
[Ghoneim, A.M.] A;Agricultural Research Center (ARC), Egypt
摘要：
<jats:p><p>Twenty hybrids were developed from crossing four environmental genic male sterile (EGMS) lines with five testers in line × tester mating design to magnitude of heterosis over better parent for grain yield and contributing traits in rice (<em>Oryza sativa </em>L.). Five hybrids ‘WTSC9059’ × ‘Sakha101’, ‘WTSC9039’ × ‘Sakha102’, ‘WTSC9059’ × ‘Sakha108’, ‘WTSC9039’ × ‘Sakha108’ and ‘WTSC9039’ × ‘Sakha101’ express superior value for number of panicles, fertility percentage, 100-grain mass, grain yield, apparent heterosis and phenotypic acceptance. The top three heterotic combinations identified for grain yield/ha were ‘WTSC9059’ × ‘Sakha101’, ‘WTSC9039’ × ‘Sakha102’ and ‘Longping’ × ‘Sakha105’ which exhibited 100.00, 71.51 and 66.61% heterobeltiosis, respectively. The lines ‘WTSC9059’ and ‘‘Longping’’ and testers ‘Sakha101’, ‘Sakha102’ and ‘Sakha108’ was found to be good general combiner for most of the characteristics and could be extensively used in future hybrid rice breeding program. The grain yield was correlated highly significant and positive with panicle exertion, panicle mass, fertility percentage and appearance of heterosis, otherwise the negative correlation and significant was found with flag leaf area.</p></jats:p>
通讯机构：
[Langtao Xiao] C;College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha, China
关键词：
Magnetic solid phase extraction;In situ derivatization;Oilseeds;Phytohormones;Ultra-high performance liquid;chromatography-tandem mass spectrometry
摘要：
Magnetic solid phase extraction integrated with in situ derivations for the profiling of 12 phytohormones in a single rapeseed seed was developed by using ultra-high performance liquid chromatography-tandem mass spectrometry. The Fe3O4@Ti3C2@beta-cyclodextrin nanoparticles were firstly synthesized and used as an adsorbent for the solid-phase extraction of phytohormones. The magnetic dispersive solid-phase extraction and in situ derivation by the addition of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide were ingeniously combined. This efficient pre-treatment method integrated the extraction, purification, and derivatization processes into one single step. Satisfactory methodological performance was achieved by optimization of the parameters. Linearities (R-2 > 0.9928) and recoveries (80.4 %-115.1%) at three spiked levels, as well as the low matrix effect (from -16.63% to 17.06%) and limits of detection (0.89-13.62 pg/mL) were obtained. The spatio-temporal profiling of target phytohormones in different tissues of rapeseed germination was investigated. This method was successfully employed for analyzing target phytohormones in different oilseeds samples.
通讯机构：
[Hou, Bing-Kai] S;Shandong Univ, Sch Life Sci, Minist Educ, Key Lab Plant Dev & Environm Adaptat Biol, Qingdao 266237, Peoples R China.
关键词：
Arabidopsis thaliana;auxin;glycosylation
摘要：
Auxin is a class of plant hormone that plays a crucial role in the life cycle of plants, particularly in the growth response of plants to ever-changing environments. Since the auxin responses are concentration-dependent and higher auxin concentrations might often be inhibitory, the optimal endogenous auxin level must be closely controlled. However, the underlying mechanism governing auxin homeostasis remains largely unknown. In this study, a UDP-glycosyltransferase (UGT76F1) was identified from Arabidopsis thaliana, which participates in the regulation of auxin homeostasis by glucosylation of indole-3-pyruvic acid (IPyA), a major precursor of the auxin indole-3-acetic acid (IAA) biosynthesis, in the formation of IPyA glucose conjugates (IPyA-Glc). In addition, UGT76F1 was found to mediate hypocotyl growth by modulating active auxin levels in a light- and temperature-dependent manner. Moreover, the transcription of UGT76F1 was demonstrated to be directly and negatively regulated by PIF4, which is a key integrator of both light and temperature signaling pathways. This study sheds a light on the trade-off between IAA biosynthesis and IPyA-Glc formation in controlling auxin levels and reveals a regulatory mechanism for plant growth adaptation to environmental changes through glucosylation of IPyA.
摘要：
Seed is vital to the conservation of germplasm and plant biodiversity. Seed dormancy is an adaptive trait in numerous seed-plant species, enabling plants to survive under stressful conditions. Seed dormancy is mainly controlled by abscisic acid (ABA) and gibberellin (GA) and can be classified as primary and secondary seed dormancy. The primary seed dormancy is induced by maternal ABA. Here we found that AtPER1, a seed-specific peroxiredoxin, is involved in enhancing primary seed dormancy. Two loss-of-function atper1 mutants, atper1-1 and atper1-2, displayed suppressed primary seed dormancy accompanied with reduced ABA and increased GA contents in seeds. Furthermore, atper1 mutant seeds were insensitive to abiotic stresses during seed germination. The expression of several ABA catabolism genes (CYP707A1, CYP707A2, and CYP707A3) and GA biosynthesis genes (GA20ox1, GA20ox3, and KAO3) in atper1 mutant seeds was increased compared to wild-type seeds. The suppressed primary seed dormancy of atper1-1 was completely reduced by deletion of CYP707A genes. Furthermore, loss-of-function of AtPER1 cannot enhance the seed germination ratio of aba2-1 or ga1-t, suggesting that AtPER1-enhanced primary seed dormancy is dependent on ABA and GA. Additionally, the level of reactive oxygen species (ROS) in atper1 mutant seeds was significantly higher than that in wild-type seeds. Taken together, our results demonstrate that AtPER1 eliminates ROS to suppress ABA catabolism and GA biosynthesis, and thus improves the primary seed dormancy and make the seeds less sensitive to adverse environmental conditions.
