外源水杨酸调控水稻化感抑草作用及其分子生理特性

为了探讨外源水杨酸（SA）调控水稻化感抑草效应的可行性，研究了不同浓度的外源SA对强化感水稻PI312777抑草效应的影响及其生理生化特性，并运用实时定量RT-PCR(FQ-PCR)技术检测SA介导的关键酶苯丙氨酸解氨酶基因（ZB8）的相对表达量.结果表明：外源SA能够诱导水稻化感抑草效应增强，而且这种诱导效应与SA的浓度和处理时间相关.叶面喷施SA后，PI312777对稗草的抑制率显著提高，其根系活力、超氧化物歧化酶（SOD）和过氧化物酶（POD）活性增强，过氧化氢酶（CAT）活性降低；而伴生杂草稗草的相应生理指标的变化趋势则相反.PI312777植株中的苯丙氨酸解氨酶（PAL）活性增强，总酚含量升高.0.2 mmol·L^-1的SA诱导水稻化感抑草效应最显著，该浓度下目的基因ZB8的相对表达丰度随处理时间先上调后下调，在24 h达到表达高峰.

Regulation effect of exogenous salicylic acid on weed suppression and molecular physiological characteristics of allelopathic rice.

To investigate the feasibility of using exogenous salicylic acid (SA) to regulate the allelopathic weed suppression of rice, this paper studied the effects of different concentrations exogenous SA on the weed-suppression and physiological-biochemical characteristics of allelopathic rice PI312777, and the relative expression quantity of gene ZB8 in the rice by real time quantitative RT-PCR (FQ-PCR). The results showed that exogenous SA induced the enhancement of the allelopathic potential of donor rice in suppressing target weed plants, and this inducing effect was SA dose and treatment time dependent. After foliar spraying SA, the inhibitory effect of PI312777 on barnyardgrass increased significantly, and the root vigor and superoxide dismutase (SOD) and perocidase (POD) activities of PI312777 increased, while its catalase (CAT) activity decreased. The reverse was true for the target weed barnyardgrass. At the same time, the phenylalanine ammonialyase (PAL) activity of PI312777 increased significantly, leading to an increase of the total content of phenols. Among the test concentrations of SA, 0.2 mmol x L(-1) had the best inducing effect, under which, the relative expression quantity of ZB8 increased first and decreased then, with a peak at 24 hours after treatment.