State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.
J Exp Bot. 2017 Dec 16;68(21-22):5923-5935. doi: 10.1093/jxb/erx394.
Previous research has shown that elevated CO2 reduces plant resistance against insects and enhances the water use efficiency of C3 plants, which improves the feeding efficiency of aphids. Although plant mitogen-activated protein kinases (MAPKs) are known to regulate water relations and phytohormone-mediated resistance, little is known about the effect of elevated CO2 on MAPKs and the cascading effects on aphids. By using stably transformed Nicotiana attenuata plants silenced in MPK4, wound-induced protein kinase (WIPK), or salicylic acid-induced protein kinase (SIPK), we determined the functions of MAPKs in plant-aphid interactions and their responses to elevated CO2. The results showed that among all plant genotypes, inverted repeat MPK4 plants had the largest stomatal apertures, the lowest water content, the strongest jasmonic acid (JA)-dependent resistance, and the lowest aphid numbers, suggesting that MPK4 affects plant responses to aphids by regulating stomatal aperture and JA-dependent resistance. Regardless of aphid infestation, elevated CO2 up-regulated MPK4, but not WIPK or SIPK, in wild-type plants. Elevated CO2 increased the number, mean relative growth rate, and feeding efficiency of aphids on all plant genotypes except inverted repeat MPK4. We conclude that MPK4 is a CO2-responsive plant determinant that regulates the molecular interaction between plants and aphids.
先前的研究表明，升高的二氧化碳会降低植物对昆虫的抵抗力，并提高 C3 植物的水分利用效率，从而提高蚜虫的取食效率。尽管植物丝裂原激活蛋白激酶（MAPKs）被认为可以调节水分关系和植物激素介导的抗性，但对于升高的二氧化碳对 MAPKs 的影响以及对蚜虫的级联效应知之甚少。通过使用稳定转化的拟南芥沉默 MPK4、伤口诱导蛋白激酶（WIPK）或水杨酸诱导蛋白激酶（SIPK），我们确定了 MAPKs 在植物-蚜虫相互作用及其对升高的二氧化碳的反应中的功能。结果表明，在所有植物基因型中，反向重复 MPK4 植株具有最大的气孔开度、最低的含水量、最强的茉莉酸（JA）依赖性抗性和最低的蚜虫数量，表明 MPK4 通过调节气孔开度和 JA 依赖性抗性来影响植物对蚜虫的反应。无论是否受到蚜虫侵害，升高的二氧化碳都会在野生型植物中上调 MPK4，但不会上调 WIPK 或 SIPK。升高的二氧化碳增加了除反向重复 MPK4 以外的所有植物基因型上蚜虫的数量、平均相对增长率和取食效率。我们得出结论，MPK4 是一种对二氧化碳有反应的植物决定因素，它调节植物与蚜虫之间的分子相互作用。
