Cell wall integrity modulates Arabidopsis thaliana cell cycle gene expression in a cytokinin- and nitrate reductase-dependent manner
Cell wall integrity modulates Arabidopsis thaliana cell cycle gene expression in a cytokinin- and nitrate reductase-dependent manner
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DOI：
10.1242/dev.166678
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发表时间：
2018-10-01
期刊：
影响因子：
4.6
通讯作者：
Hamann, Thorsten
中科院分区：
文献类型：
--
作者：
Gigli-Bisceglia, Nora;Engelsdorf, Timo;Hamann, Thorsten
在植物生长和防御过程中，细胞周期活动需要与细胞壁的完整性相协调。人们对这种协调是如何实现的知之甚少。在这里，我们研究了协调拟南芥幼苗细胞壁损伤（CWD，纤维素生物合成抑制引起的）细胞分裂素稳态，细胞周期基因表达和根尖细胞形状的影响。CWD能敏感地抑制细胞周期基因的表达，增加移行带细胞的宽度。这些结果与CWD诱导的细胞分裂素稳态的敏感性变化相关。细胞分裂素氧化酶/脱氢酶2和3（CKX 2，CKX 3），编码细胞分裂素降解酶的表达，诱导CWD和减少的阿托伐他汀治疗。在硝酸还原酶1硝酸还原酶2（nia 1 nia 2）幼苗，CKX 2和CKX 3的转录水平没有增加，细胞周期基因的表达没有被CWD抑制。此外，建立CWD诱导的反应，如茉莉酸，水杨酸和木质素的生产，也不存在，这意味着中央的作用NIA 1/2介导的过程中的CWD反应的调节。这些结果表明，CWD通过NIA 1/2介导的过程增强细胞分裂素降解速率，导致细胞周期基因表达的衰减。
During plant growth and defense, cell cycle activity needs to be coordinated with cell wall integrity. Little is known about how this coordination is achieved. Here, we investigated coordination in Arabidopsis thaliana seedlings by studying the impact of cell wall damage (CWD, caused by cellulose biosynthesis inhibition) on cytokinin homeostasis, cell cycle gene expression and cell shape in root tips. CWD inhibited cell cycle gene expression and increased transition zone cell width in an osmosensitive manner. These results were correlated with CWD-induced, osmosensitive changes in cytokinin homeostasis. Expression of CYTOKININ OXIDASE/DEHYDROGENASE 2 and 3 (CKX2, CKX3), which encode cytokinin-degrading enzymes, was induced by CWD and reduced by osmoticum treatment. In nitrate reductase1 nitrate reductase2 (nia1 nia2) seedlings, CKX2 and CKX3 transcript levels were not increased and cell cycle gene expression was not repressed by CWD. Moreover, established CWD-induced responses, such as jasmonic acid, salicylic acid and lignin production, were also absent, implying a central role of NIA1/2-mediated processes in regulation of CWD responses. These results suggest that CWD enhances cytokinin degradation rates through a NIA1/2-mediated process, leading to attenuation of cell cycle gene expression.