玉米萌发成苗期渗透调节机制的研究进展

Research Progress in Mechanism of Osmotic Adjustment at Germination and Emergence Stage in Maize

稳定和增加玉米产量有助于确保我国的粮食供应安全,而良好的种子萌发和成苗是玉米高产的基础。玉米种子萌发和成苗受春旱影响严重,渗透调节是该时期抵御干旱的关键机制之一,不同玉米基因型的渗透调节能力存在差异。在玉米萌发成苗期,积累的渗调物质包括无机离子和有机物质。其中,钾离子是主要的无机渗调物质,其吸收和分配受膜钾转运蛋白和质子ATP酶调节;可溶性糖是重要的有机渗调物质,其形成和运输受淀粉酶、磷酸蔗糖合成酶、蔗糖转化酶等的调节;随着干旱胁迫的延长,可溶性蛋白、游离氨基酸、脯氨酸和甜菜碱对抗旱性的贡献逐渐增大;脱落酸(ABA)是种子萌发期渗透调节作用的重要调节者,ABA的作用受其合成、分解能力和信号通路组分变化的影响;玉米的渗透调节能力也受ZmPtil、ZmPtil-1、ZmCIPK2、ZmSAMS1、ZmC2H2-1等基因表达的调节。

Stabilizing and increasing corn production will help to ensure food supply security in our country,and good seed germination and emergence are the basis for high yield of maize.The seed germination and emergence are seriously affected by drought stress during spring,and osmotic adjustment is one of the key mechanisms to resist drought in this period.There are differences in osmotic adjustment among different maize genotypes.At the stage of germination and emergence in maize,accumulated osmolytes include inorganic ions and organic substances.Among them,potassium ion is the main inorganic osmolyte.Its absorption and distribution are regulated by potassium transporters and proton ATPases on membrane.Soluble sugar is an important organic osmolyte.Its formation and transport are regulated by amylase,sucrose phosphate synthase and invertin.With prolonged period of drought stress,soluble proteins,free amino acids,proline and betaines gradually increase their contribution to drought resistance.Abscisic acid(ABA)is an important regulator of osmotic adjustment at seed germination and emergence stage,and the effect of ABA is affected by synthesis,degradation and changes in signal pathways.The osmotic adjustment in maize is also regulated by expression of ZmPtil,ZmPtil-1,ZmCIPK2,ZmSAMS1 and ZmC2H2-1.