A salivary calcium-binding protein from Laodelphax striatellus acts as an effector that suppresses defense in rice
A salivary calcium-binding protein from Laodelphax striatellus acts as an effector that suppresses defense in rice
复制标题
来自灰飞虱的唾液钙结合蛋白充当抑制水稻防御的效应子。
DOI：
10.1002/ps.6252
复制
发表时间：
2021-02-25
影响因子：
4.1
通讯作者：
Zhu-Salzman, Keyan
中科院分区：
文献类型：
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作者：
Tian, Tian;Ji, Rui;Zhu-Salzman, Keyan
背景
植食性昆虫唾液中的钙（Ca 2+）结合蛋白作为效应物减弱宿主植物的防御，从而改善昆虫的取食性能。因此，通过转基因植物介导的RNAi沉默这些基因是一种有前途的害虫控制策略。然而，其序列和功能在小褐飞虱灰飞虱（SBPH）仍有待研究。
结果
我们确定了一个假定的EF-手钙离子结合蛋白（LsECP 1）在SBPH水样唾液。LsECP 1在唾液腺中表达极高，但在卵期表达水平较低。LsECP 1在水稻细胞中的瞬时表达表明其定位于细胞质和细胞核。细菌表达的重组LsECP 1蛋白具有Ca 2+结合活性。水稻植株的SBPH EMP 1基因敲低，表现出较高水平的胞质Ca 2+，茉莉酸（JA），茉莉酰异亮氨酸（JA-Ile），和H2 O2 ;一致的，应用异源表达的LsECP 1蛋白抑制水稻损伤诱导的JA，JA-Ile，和H2 O2的积累。因此，通过注射dsRNA敲低LsECP 1导致在水稻植株上饲养的SBPH的摄食、繁殖力和存活率降低。获得了组成型表达LsECP 1 dsRNA的转基因水稻植株，植物介导的LsECP 1敲低增强了水稻对SBPH的抗性。
结论
SBPH LsECP 1作为一种效应子，能够削弱寄主水稻的防御反应，促进SBPH的生长。这一发现为植物介导的基于RNAi的害虫管理提供了潜在的基因靶标。本文受版权保护。All rights reserved.
BACKGROUND
Calcium (Ca2+ )-binding proteins in the saliva of herbivorous insects function as effectors to attenuate host plant defenses and thus improve insect feeding performance. Silencing these genes via transgenic plant-mediated RNAi is thus a promising pest control strategy. However, their sequences and functions in the small brown planthopper Laodelphax striatellus (SBPH) remain to be investigated.
RESULTS
We identified a putative EF-hand Ca2+ -binding protein (LsECP1) in SBPH watery saliva. LsECP1 was expressed extremely high in the salivary glands but at a low level during the egg stage. Transient LsECP1 expression in rice cells indicated its cytoplasm and nucleus localization. The bacterially expressed recombinant LsECP1 protein exhibited Ca2+ -binding activity. Rice plants fed by SBPH nymphs with knocked down LsECP1 exhibited higher levels of cytosolic Ca2+ , jasmonic acid (JA), jasmonoyl-isoleucine (JA-Ile), and H2 O2 ; Consistently, application of heterogeneously expressed LsECP1 protein suppressed wound-induced JA, JA-Ile, and H2 O2 accumulation in rice. Thus, LsECP1 knockdown by dsRNA injection resulted in reduced feeding, fecundity, and survival rates of SBPH reared on rice plants. Transgenic rice plants constitutively expressing LsECP1 dsRNA were produced, and plant-mediated LsECP1 knockdown enhanced rice resistance to SBPH.
CONCLUSION
SBPH LsECP1 acts as an effector to impair host rice defense responses and promotes SBPH performance. This discovery provides a potential gene target for plant-mediated RNAi-based pest management. This article is protected by copyright. All rights reserved.