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干旱是影响植物生长发育最主要的逆境因子。植物在水分胁迫下会引起一系列分子反应和信号传递,干旱胁迫诱导基因表达一些重要的功能蛋白和调节蛋白以保护细胞不受水分胁迫的伤害。目前已研究证实相关蛋白有跨膜运输蛋白(水通道蛋白、ATP酶等)、水分胁迫调节剂(K~+、Na~+、蔗糖、脯氨酸、甜菜碱等)、运输或合成相关的酶、Lea蛋白、抗氧化作用相关的酶(SOD、CAT等)、水分胁迫蛋白、调控蛋白(蛋白激酶、转录因子)等。干旱胁迫诱导基因的活化至少涉及4条途径:植物细胞可能通过膨压变化或膜受体的构象变化感知水分胁迫,将胞外信号转为胞内信号,从而触发相应的信号途径,并可导致第二信使(Ca~(2+)、IP_3等)生成,在这原始信号被逐级传递放大的过程中,其中2条传递途径是依赖ABA的,另外2条传递途径是不依赖ABA的。通过基因表达调控已分析鉴定出一些水分胁迫有关的顺式作用元件(ABRE、DRE、Myc等)和转录因子(bzip、DREBP、MYC/MYB等)。
Drought is the most important adverse factor affecting plant growth and development. Under water stress, plants induce a series of molecular responses and signal transduction. Drought stress induces genes to express important functional and regulatory proteins to protect cells from water stress. At present, it has been confirmed that the related proteins are transmembrane transport proteins (aquaporin, ATPase, etc.), water stress regulators (K ~ +, Na ~ +, sucrose, proline, betaine, etc.) Enzyme, Lea protein, antioxidase-related enzymes (SOD, CAT, etc.), water stress proteins, regulatory proteins (protein kinases, transcription factors) and the like. At least four pathways are involved in the activation of genes induced by drought stress: plant cells may sense extracellular signal through intracellular signal through turgor change or conformational change of membrane receptors, triggering corresponding signal pathway and may lead to The second messenger (Ca ~ (2 +), IP_3, etc.) is generated. When the original signal is transmitted and amplified step by step, two of the two messengers are ABA-dependent and the other two are independent of ABA. Some water stress-related cis-acting elements (ABRE, DRE, Myc, etc.) and transcription factors (bzip, DREBP, MYC / MYB, etc.) have been identified through the regulation of gene expression.