Cellulose defects in the Arabidopsis secondary cell wall promote early chloroplast development.
Cellulose defects in the Arabidopsis secondary cell wall promote early chloroplast development.
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DOI：
10.1111/tpj.14527
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Duorong Xu;Ravi Dhiman;A. Garibay;H. Mock;D. Leister;T. Kleine
中科院分区：
文献类型：
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作者：
Duorong Xu;Ravi Dhiman;A. Garibay;H. Mock;D. Leister;T. Kleine
林可霉素（LIN）介导的叶绿体蛋白质合成抑制可防止幼苗变绿，抑制细胞核中光合作用相关基因（包括LHCB 1.2）的活性，并诱导类苯丙素途径，导致花青素的产生。在基因组解偶联（枪）突变体中，LHCB 1.2表达在LIN或其他早期叶绿体发育抑制剂存在下维持。在筛选中，使用的LIN浓度低于用于分离枪突变体的LIN浓度，我们已经鉴定出对林可霉素（holi）满意的突变体。几个holi突变体表现出增加的耐受性LIN，表现出去阻遏LHCB 1.2的表达和叶绿素合成的幼苗。通过全基因组SNP作图鉴定了相关突变，发现大多数突变影响苯丙烷途径。然而，LHCB 1.2的表达似乎不直接调节苯丙烷类，突变体的代谢谱所示。最有效的霍利突变体是缺陷的不规则的XYLEM3编码的纤维素合酶的亚基，和比较分析，这和其他细胞壁突变体建立了二级细胞壁的完整性和早期叶绿体发育之间的联系，可能涉及改变阿坝代谢或传感。
Lincomycin (LIN)-mediated inhibition of protein synthesis in chloroplasts prevents greening of seedlings, represses the activity of photosynthesis-related genes in the nucleus including LHCB1.2, and induces the phenylpropanoid pathway, resulting in production of anthocyanins. In genomes uncoupled (gun) mutants, LHCB1.2 expression is maintained in the presence of LIN or other inhibitors of early chloroplast development. In a screen using concentrations of LIN lower than those employed to isolate gun mutants, we have identified happy on lincomycin (holi) mutants. Several holi mutants show increased tolerance to LIN, exhibiting de-repressed LHCB1.2 expression and chlorophyll synthesis in seedlings. The mutations responsible were identified by whole-genome SNP mapping, and most were found to affect the phenylpropanoid pathway. However, LHCB1.2 expression appears not to be directly regulated by phenylpropanoids, as indicated by metabolic profiling of mutants. The most potent holi mutant is defective in a subunit of cellulose synthase encoded by IRREGULAR XYLEM3, and comparative analysis of this and other cell-wall mutants establishes a link between secondary cell-wall integrity and early chloroplast development, possibly involving altered ABA metabolism or sensing.