Phototropin2-mediated hypocotyl phototropism is negatively regulated by JAC1 and RPT2 in Arabidopsis
Phototropin2-mediated hypocotyl phototropism is negatively regulated by JAC1 and RPT2 in Arabidopsis
复制标题
拟南芥中向光素2介导的下胚轴向光性受到JAC1和RPT2的负调节
DOI：
10.1016/j.plaphy.2021.05.007
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发表时间：
2021
影响因子：
6.5
通讯作者：
Xiao Zhang
中科院分区：
文献类型：
--
作者：
Jindong Zhu;Jing Wang;Yuanyuan Sheng;Yan Tian;Yueyue Zhang;Chanjuan Zhou;Xiang Zhao;Xiao Zhang
在蓝光作用下，下胚轴的趋光性由两种蓝光受体光敏素Ph_1和P_2冗余地介导。随着光强的增加，P_1和P_2抑制了光_2介导的反应。到目前为止，只有拟南芥根趋光性(RPT2)被证明参与了光1介导的趋光性的抑制。为了剖析光抑制的信号网络，我们对RPT2相互作用蛋白进行了酵母双杂交(Y2H)筛选，并鉴定了叶绿体积累反应1(JAC1)所需的J结构域蛋白。通过双分子荧光互补和Co-IP分析证实了JAC1和RPT2之间的相互作用，JAC1主要在子叶和下胚轴中表达。与RPT2一样，JAC1也能被蓝光诱导，提示JAC1在抑制向光性方面可能与RPT2相似。遗传分析表明，该突变显著促进了突变体下胚轴对中等强度蓝光的弯曲，并且这种作用被突变体中JAC1的结构性表达所抑制。与光1突变体相比，光1 rpt2双突变体也表现出更强的向光性。综上所述，我们的数据清楚地表明，JAC1与RPT2合作负向调节植物的下胚轴向光性，并可能作用于Photo1的下游或与其平行。
Hypocotyl phototropism is redundantly mediated by phot1 and phot2, two blue light receptor phototropins, under the intensity of blue light>1 μmol m−2s−1. As light intensity increases, phot1 inhibits the phot2-mediated response. To date, onlyArabidopsisRoot Phototropism2 (RPT2) has been shown to participate in phot1-mediated inhibition of phototropism. To dissect the signaling network that underlies phot1-mediated inhibition, we carried out a yeast two-hybrid (Y2H) screening assay for RPT2 interacting proteins and identified J-domain protein required for chloroplast accumulation response 1 (JAC1). The interaction between JAC1 and RPT2 was verified by bimolecular fluorescence complementation and Co-IP assays.JAC1is expressed mainly in cotyledons and hypocotyls. LikeRPT2,JAC1can be induced by blue light, suggesting that it may function similarly to RPT2 in the inhibition of phototropism. Genetic analysis showed thatjac1mutation significantly enhanced the hypocotyl bending ofphot1mutants towards intermediate-intensity blue light, and this effect was inhibited by the constitutive expression of JAC1 in thephot1 jac1mutant. Thephot1 rpt2 double mutant also exhibited enhanced phototropism compared with thephot1mutant. Taken together, our data clearly demonstrate that JAC1 cooperates with RPT2 to negatively regulate hypocotyl phototropism in plants and may act either downstream of or in parallel with phot1.