Abstract:
The gene encoding 9-cis-epoxycarotenoid dioxygenase 3 (NCED3) functions in abscisic acid (ABA) biosynthesis, plant growth and development, and tolerance to adverse temperatures, drought and saline conditions. In this study, three rice lines were used to explore the function of OsNCED3, these included an OsNCED3-overexpressing line (OsNCED3-OE), a knockdown line (osnced3-RNAi) and wild-type rice (WT). These rice lines were infested with the brown plant hopper (BPH; Nilaparvata lugens) and examined for physiological and biochemical changes, hormone content, and defense gene expression. The results showed that OsNCED3 activated rice defense mechanisms, which led to an increased defense enzyme activity of superoxide dismutase, peroxidase, and polyphenol oxidase. The overexpression of OsNCED3 decreased the number of planthoppers and reduced oviposition and BPH hatching rates. Furthermore, the overexpression of OsNCED3 increased the concentrations of jasmonic acid, jasmonyl-isoleucine and ABA relative to WT rice and the osnced3-RNAi line. These results indicate that OsNCED3 improved the stress tolerance in rice and support a role for both jasmonates and ABA as defense compounds in the rice-BPH interaction.
摘要:
编码9-顺式-环氧类胡萝卜素双加氧酶3(NCED3)的基因在脱落酸(ABA)生物合成中起作用,植物生长发育,和对不利温度的耐受性,干旱和盐水条件。在这项研究中,使用三个水稻品系来探索OsNCED3的功能,其中包括OsNCED3过表达品系(OsNCED3-OE),敲除系(osnced3-RNAi)和野生型水稻(WT)。这些水稻品系被棕色植物料斗(BPH;Nilapavatalugens)侵染,并检查生理和生化变化,激素含量,和防御基因表达。结果表明,OsNCED3激活了水稻防御机制,导致超氧化物歧化酶的防御酶活性增加,过氧化物酶,和多酚氧化酶。OsNCED3的过表达减少了飞虱的数量,降低了产卵和BPH孵化率。此外,OsNCED3的过表达增加了茉莉酸的浓度,相对于WT水稻和osnced3-RNAi系,茉莉酰基-异亮氨酸和ABA。这些结果表明,OsNCED3提高了水稻的抗逆性,并支持茉莉酸和ABA作为防御化合物在水稻-BPH相互作用中的作用。