AUTHOR=Chen Xuexue , Gu Xiaojiao , Gao Fan , Guo Jiaxuan , Shen Yuanyue 

TITLE=The protein kinase FvRIPK1 regulates plant morphogenesis by ABA signaling using seed genetic transformation in strawberry

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1026571

DOI=10.3389/fpls.2022.1026571

ISSN=1664-462X

ABSTRACT=<p>A strawberry RIPK1, a leu-rich repeat receptor-like protein kinase, is previously demonstrated to be involved in fruit ripening as a positive regulator; however, its role in vegetable growth remains unknown. Here, based on our first establishment of <italic>Agrobacterium</italic>-mediated transformation of germinating seeds in diploid strawberry by <italic>FvCHLH</italic>/<italic>FvABAR</italic>, a reporter gene that functioned in chlorophyll biosynthesis, we got <italic>FvRIPK1-RNAi</italic> mutants. Downregulation of <italic>FvRIPK1</italic> inhibited plant morphogenesis, showing curled leaves; also, this silencing significantly reduced <italic>FvABAR</italic> and <italic>FvABI1</italic> transcripts and promoted <italic>FvABI4</italic>, <italic>FvSnRK2.2</italic>, and <italic>FvSnRK2.6</italic> transcripts. Interestingly, the downregulation of the <italic>FvCHLH/ABAR</italic> expression could not affect <italic>FvRIPK1</italic> transcripts but remarkably reduced <italic>FvABI1</italic> transcripts and promoted <italic>FvABI4</italic>, <italic>FvSnRK2.2</italic>, and <italic>FvSnRK2.6</italic> transcripts in the contrast of the non-transgenic plants to the <italic>FvCHLH</italic>/<italic>FvABAR</italic>-RNAi plants, in which chlorophyll contents were not affected but had abscisic acid (ABA) response in stomata movement and drought stress. The distinct expression level of <italic>FvABI1</italic> and <italic>FvABI4</italic>, together with the similar expression level of <italic>FvSnRK2.2</italic> and <italic>FvSnRK2.6</italic> in the <italic>FvRIPK1</italic>- and <italic>FvABAR/CHLH</italic>-RNAi plants, suggested that FvRIPK1 regulated plant morphogenesis probably by ABA signaling. In addition, FvRIPK1 interacted with FvSnRK2.6 and phosphorylated each other, thus forming the FvRIPK1–FvSnRK2.6 complex. In conclusion, our results provide new insights into the molecular mechanism of FvRIPK1 in plant growth.</p>