Nguyen HTK, Hyoung S, Kim HJ, Cho KM, Shin JS. The transcription factor
γMYB2 acts as a negative regulator of secondary cell wall thickening in anther and stem.
Gene 2019;
702:158-165. [PMID:
30930225 DOI:
10.1016/j.gene.2019.03.061]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 01/06/2023]
Abstract
Secondary cell wall (SCW) thickening provides the mechanical force for anther dehiscence and plays an important role in the formation of xylem structure. We have previously reported that γMYB2, a MYB coiled-coil protein, directly binds to the P1BS cis-element of the PLA2-γ promoter and acts as a co-activator of γMYB1 in controlling the expression of PLA2-γ. In this study, we analyzed morphological phenotypes of the constitutive overexpression (γMYB2-OE) and knock-down (γMYB2-KD) lines of γMYB2. We found that γMYB2 overexpression caused the collapse of the endothecium layer, thereby suppressing anther dehiscence and forming short infertile siliques. The γMYB2-OE also showed less cellulose deposition in the xylem and had a longer primary stem than the wild-type, while γMYB2-KD had greater cellulose accumulation and a shorter primary stem than the wild-type. We demonstrated that the male sterility and the longer primary stem in γMYB2-OE were caused by reduced expression of SCW thickening-related genes. Our results suggest that γMYB2 acts as a negative regulator in controlling the SCW thickening in Arabidopsis.
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