玉米适应钾胁迫的重要途径是刺激侧根分化和伸长，调节根系构型，进而提高土壤钾素的吸收利用效率。然而，关于低钾胁迫下玉米调节根系构型变化的生理机制仍了解甚少。在前期研究基础上，本研究认为耐低钾玉米自交系促进侧根分化和伸长可能受生长素（IAA）途径和脱落酸（ABA）途径协同调节。本研究利用课题组前期筛选出的典型耐低钾（90-21-3、099）和不耐低钾（D937、835）玉米自交系为材料，在正常钾和低钾胁迫处理下，采用IAA和ABA途径外源处理，研究根系侧根分化和伸长、根系构型变化、细胞超显微结构、活性氧（ROS）分布、抗氧化酶活性、激素水平、转运蛋白和钾离子通道基因表达等方面内容，阐明IAA途径协同ABA途径调节侧根分化和伸长的生理机制，为玉米钾高效利用育种提高科学依据。

One of the effective approaches for maize to adapt potassium (K) deficiency is to stimulate lateral-root formation and elongation, regulate root architecture and improve K absorption and utilization efficiency from soil. However, the physiology mechanism of root regulation in K deficiency is still unclear. Based on our previous studies, we imagined that the IAA pathway and ABA pathway coordinately regulated maize lateral-root formation and elongation under K deficiency. In present study, four representative maize inbred lines screened from our previous studies, “90-21-3 and 099” tolerance to K+ deficiency and “D937 and 835” sensitive to K+ deficiency, were carried out to compare the difference with exogenous IAA and ABA application under +K and –K treatments. The important resistant traits will be investigated, including lateral-root formation and elongation, root architecture variation, cell sub-microstructure structure, ROS distribution, antioxidant enzyme activities, hormone level, expression of IAA and ABA transporters and K+ channel genes etc. This research should explore the relationship between IAA pathway and ABA pathway on regulating lateral-root development under K deficiency, and improve K utilization efficiency of maize breeding program.