■锰(Mn)在植物的生长发育中起着举足轻重的作用。除了帮助植物生长和发育,锰作为重金属(HM)在土壤中过量施用时可能是有毒的。桑树是一种具有经济意义的植物,能够适应一系列环境条件,并具有HMs对污染土壤进行植物修复的潜力。M.alba耐受Mn胁迫的机制仍然不清楚。
■在这项研究中,锰浓度包含充足性(0.15mM),更高的方案(1.5mM和3mM),和缺乏(0mM和0.03mM),在盆栽处理中应用M.alba21天,以了解M.alba对锰的耐受性。Mn胁迫对净光合速率(Pn)的影响,气孔导度(Gs),蒸腾速率(Tr),细胞间CO2浓度(Ci),叶绿素含量,植物形态性状,通过非靶向LC-MS技术分析酶和非酶参数以及代谢组特征。
■锰缺乏和毒性降低植物生物量,Pn,Ci,Gs,Tr,和叶绿素含量。锰胁迫导致过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性下降,而过氧化物酶(POD)活性,和叶锰含量,增加。可溶性糖,可溶性蛋白质,丙二醛(MDA)和脯氨酸的锰缺乏和毒性浓度升高。代谢组学分析表明,Mn浓度诱导1031种差异表达的代谢物(DEM),特别是氨基酸,脂质,碳水化合物,苯及其衍生物和次生代谢物。DEM在α-亚麻酸代谢中显著富集,不饱和脂肪酸的生物合成,半乳糖代谢,泛酸和CoA生物合成,戊糖磷酸途径,碳代谢,等。
■半乳糖醇的上调,肌醇,茉莉酸,L-天冬氨酸,卟啉I,Trigonelline,泛醇,和泛酸及其在代谢途径中的重要性使它们在M.alba中具有Mn胁迫耐受性代谢产物。我们的发现揭示了DEM对M.alba对锰营养的反应和所涉及的代谢机制的基本理解,这可能对推进M.alba遗传改良计划和植物修复计划具有潜在的意义。
UNASSIGNED: Manganese (Mn) plays a pivotal role in plant growth and development. Aside aiding in plant growth and development, Mn as heavy metal (HM) can be toxic in soil when applied in excess. Morus alba is an economically significant plant, capable of adapting to a range of environmental conditions and possessing the potential for phytoremediation of contaminated soil by HMs. The mechanism by which M. alba tolerates Mn stresses remains obscure.
UNASSIGNED: In this study, Mn concentrations comprising sufficiency (0.15 mM), higher regimes (1.5 mM and 3 mM), and deficiency (0 mM and 0.03 mM), were applied to M. alba in pot treatment for 21 days to understand M. alba Mn tolerance. Mn stress effects on the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), intercellular CO2 concentration (Ci), chlorophyll content, plant morphological traits, enzymatic and non-enzymatic parameters were analyzed as well as metabolome signatures via non-targeted LC-MS technique.
UNASSIGNED: Mn deficiency and toxicity decrease plant biomass, Pn, Ci, Gs, Tr, and chlorophyll content. Mn stresses induced a decline in the activities of catalase (CAT) and superoxide dismutase (SOD), while peroxidase (POD) activity, and leaf Mn content, increased. Soluble sugars, soluble proteins, malondialdehyde (MDA) and proline exhibited an elevation in Mn deficiency and toxicity concentrations. Metabolomic analysis indicates that Mn concentrations induced 1031 differentially expressed metabolites (DEMs), particularly amino acids, lipids, carbohydrates, benzene and derivatives and secondary metabolites. The DEMs are significantly enriched in alpha-linolenic acid metabolism, biosynthesis of unsaturated fatty acids, galactose metabolism, pantothenate and CoA biosynthesis, pentose phosphate pathway, carbon metabolism, etc.
UNASSIGNED: The upregulation of Galactinol, Myo-inositol, Jasmonic acid, L-aspartic acid, Coproporphyrin I, Trigonelline, Pantothenol, and Pantothenate and their significance in the metabolic pathways makes them Mn stress tolerance metabolites in M. alba. Our findings reveal the fundamental understanding of DEMs in M. alba\'s response to Mn nutrition and the metabolic mechanisms involved, which may hold potential significance for the advancement of M. alba genetic improvement initiatives and phytoremediation programs.