Vitellogenin from planthopper oral secretion acts as a novel effector to impair plant defenses
Vitellogenin from planthopper oral secretion acts as a novel effector to impair plant defenses
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飞虱口腔分泌物中的卵黄蛋白原可作为削弱植物防御的新型效应物
DOI：
10.1111/nph.17620
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发表时间：
2021-08-19
期刊：
影响因子：
9.4
通讯作者：
Fang, Jichao
中科院分区：
文献类型：
--
作者：
Ji, Rui;Fu, Jianmei;Fang, Jichao
卵黄蛋白原（Vitellogenin，Vg）是一种营养丰富的蛋白质，在包括昆虫在内的几乎所有卵生动物的生殖过程中都起着重要作用。最近，Vg已被检测到唾液蛋白质组的几个刺吸草食性节肢动物，包括小褐飞虱（灰飞虱，SBPH）。然而，它的功能仍然未被探索。通过RNA干扰、植物激素和H2 O2分析、蛋白质-蛋白质相互作用研究和草食动物生物测定，研究了SBPH口服分泌Vg介导的植物-昆虫相互作用的分子机制。SBPH中的Vg C端多肽（VgC）分泌到水稻植株中后，作为一种新的效应物减弱宿主水稻的防御，从而改善昆虫的取食性能。沉默Vg减少了昆虫在水稻上的取食和存活。Vg-沉默SBPH的昆虫始终引起较高的H2 O2生产，一个完善的防御机制，在水稻，而VgC在植物中的表达显着阻碍过氧化氢（H2 O2）的积累，促进昆虫的性能。VgC直接与水稻转录因子OsWRKY 71相互作用，OsWRKY 71是一种参与诱导H2 O2积累和植物对SBPH抗性的蛋白。这些发现表明一种新的效应功能的Vg：当分泌到宿主水稻植物，这种蛋白质有效地削弱过氧化氢介导的植物防御，通过其与植物免疫调节剂。
Vitellogenin (Vg) is a well-known nutritious protein involved in reproduction in nearly all oviparous animals, including insects. Recently, Vg has been detected in saliva proteomes of several piercing-sucking herbivorous arthropods, including the small brown planthopper (Laodelphax striatellus, SBPH). Its function, however, remains unexplored. We investigated the molecular mechanism underlying SBPH orally secreted Vg-mediated manipulation of plant-insect interaction by RNA interference, phytohormone and H2O2 profiling, protein-protein interaction studies and herbivore bioassays. A C-terminal polypeptide of Vg (VgC) in SBPH, when secreted into rice plants, acted as a novel effector to attenuate host rice defenses, which in turn improved insect feeding performance. Silencing Vg reduced insect feeding and survival on rice. Vg-silenced SBPH nymphs consistently elicited higher H2O2 production, a well-established defense mechanism in rice, whereas expression of VgC in planta significantly hindered hydrogen peroxide (H2O2) accumulation and promoted insect performance. VgC interacted directly with the rice transcription factor OsWRKY71, a protein which is involved in induction of H2O2 accumulation and plant resistance to SBPH. These findings indicate a novel effector function of Vg: when secreted into host rice plants, this protein effectively weakened H2O2-mediated plant defense through its association with a plant immunity regulator.