拟南芥突变体种子休眠与萌发的研究进展

种子的休眠和萌发是一个复杂的过程, 至今尚未能清楚阐明其调控机制。目前已从拟南芥突变体中鉴定了一些与种子萌发和休眠相关的基因, 有助于阐明种子休眠和萌发的分子机制。本文综述了拟南芥突变体种子休眠与萌发方面的研究进展。赤霉素是促进种子萌发的主要因素之一, RGL、SPY、GCR、SLY和GAR等基因的表达参与赤霉素对种子萌发的调控。脱落酸与种子休眠有关, ABI1、ABI2、ABI3、ABI4、ABI5、FUS3、LEC、MARD和CIPK等基因参与了脱落酸的调控过程。对3类乙烯反应的突变体 (ein、etr和ctr) 以及油菜素内酯突变体 (det和bri) 的研究表明乙烯和油菜素内酯是通过拮抗脱落酸而促进种子萌发的。光对种子萌发的调节, 是通过具有Ser/Thr蛋白激酶活性的光敏色素PhyA、PhyB、 PhyC、PhyD和PhyE, 以磷酸化/去磷酸化方式调节其它与萌发相关基因的表达。含氮化合物对种子萌发的促进, 可能是以一种依赖一氧化氮的方式解除种子休眠。

Progress in Seed Dormancy and Germination of Arabidopsis Mutants

Seed dormancy and germination are complicated processes, and their mechanisms to date are still unclear. However, some genes correlated with seed dormancy and germination have been identified from Arabidopsis mutants, which would be helpful in understanding the mechanisms of seed germination and dormancy. Gibberellic acid (GA) is one of the key factors promoting seed germination. Genes such as RGL, SPY, GCR, SLY and GAR are involved in the GA promotion of seed germination, whereas ABI1, ABI2, ABI3, ABI4, ABI5, FUS3, LEC, MARD and CIPK are relevant to the induction of abscisic acid (ABA) in seed dormancy. Research results involving the ethylene mutants of ein, etr, and ctr and the brassinosteroid mutants det and bri indicated that both ethylene and brassinosteroids promote seed germination via counteracting the inhibitory effects of ABA. The phytochromes PhyA, PhyB, PhyC, PhyD and PhyE are light receptors that regulate the expression of other germination-related genes by phosphorylation. Nitrogenous compounds could release dormancy in a way depending on nitric oxide.