水分胁迫对玉米幼苗生长和内源化学信号的影响

Effects of Water Stress on Growth and Endogenous Chemical Signals of Maize Seedlings

针对干旱胁迫对玉米生长发育带来不利影响的问题,通过分根水培试验,研究充分供水处理(CK)、局部水分胁迫处理(CP)和水分胁迫后局部复水处理(SP)对玉米生长和内源化学信号的影响。结果表明:CP在6~12 d时地上部干质量增长速率为117.92%,显著大于CK的90.85%,SP在0~3 d时的地上部干质量增长速率为137.65%,显著大于CK的104.15%;SP的根系导水率与根系表面积(R^(2)分别为0.832和0.825)、根系导水率与叶面积(R^(2)分别为0.904和0.937)和地上部干质量与叶面积(R^(2)为0.913)之间成显著正相关,CP各指标的相关性系数显著大于SP;CP和SP有利于叶片中脱落酸(ABA)的累积,抑制CKs和NO_(3)^(-)分泌,1 d时即可发生明显的反应,1~3 d时SP影响程度显著大于CP,之后CP的影响程度显著大于SP。CP和SP均可起到强化补偿效应的目的,但ABA、CKs和NO_(3)^(-)三者共同作用导致了CP补偿效应较SP更持久。该研究结果揭示了玉米响应非均匀水分胁迫的补偿生长机制,将局部水分胁迫与农业应用有效结合,将是提高玉米生产和水分高效利用的关键策略。

To address the problem that drought stress adversely affects maize growth and development,the effects of treatment with full water supply(CK),treatment with local water stress(CP)and treatment with local rewater after water stress(SP)on maize growth and endogenous chemical signal were studied.The results show that the above-ground dry mass growth rate of CP at 6~12 d is 117.92%,significantly higher than that of CK with 90.85%,and the above-ground dry mass growth rate of SP at 0~3 d is 137.65%,significantly higher than that of CK with 104.15%.There are significant positive correlations between root hydraulic conductivity and root surface area(R^(2) are 0.832 and 0.825),root hydraulic conductivity and leaf area(R^(2) are 0.904 and 0.937),above-ground dry mass and leaf area(R^(2) is 0.913).The correlation coefficients of CP are significantly higher than those of SP.CP and SP are beneficial to the accumulation of abscisic acid(ABA)in leaves and inhibite the secretion of CKs and NO_(3)^(-).The obvious reaction occurrs at 1 d.The effect of SP is significantly greater than that of CP at 1~3 d,and then the effect of CP is significantly greater than that of SP.Both CP and SP enhance the compensatory effect,but the combined effect of ABA,CKs and NO-3 result in a longer lasting compensatory effect of CP than SP.The results of this study reveal the compensatory growth mechanism of maize in response to non-uniform water stress.The effective combination of local water stress and agricultural application will be a key strategy to improve maize production and efficient water use.