ABNORMAL SHOOT 6 interacts with KATANIN 1 and SHADE AVOIDANCE 4 to promote cortical microtubule severing and ordering inArabidopsis
ABNORMAL SHOOT 6 interacts with KATANIN 1 and SHADE AVOIDANCE 4 to promote cortical microtubule severing and ordering inArabidopsis
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ABNORMAL SHOOT 6 与 KATANIN 1 和 SHADE AVOIDANCE 4 相互作用促进拟南芥中皮质微管的切断和排序
DOI：
10.1111/jipb.13003
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发表时间：
2020-10-02
影响因子：
11.4
通讯作者：
Liu, Xiayan
中科院分区：
文献类型：
--
作者：
Li, Yuanfeng;Deng, Meng;Liu, Xiayan
植物间期皮质微管（cMTs）介导各向异性细胞扩增，以响应环境和发育线索。在拟南芥中，KATANIN 1 （KTN1）是保守的mt切断酶KATANIN的p60催化亚基，对cMT排序和各向异性细胞扩增至关重要。然而，ktn1介导的cMT切断和排序的调控尚不清楚。在这项工作中，我们报道了拟南芥isiq67 DOMAIN （IQD）家族基因abnormal SHOOT 6（ABS6）编码一个mt相关蛋白。abs6的过表达导致子叶拉长，细胞定向铺装扩张，以及高度有序的横向cMT排列。遗传抑制因子分析显示，abs6介导的cMT排序依赖于KTN1和SHADE避免4 （SAV4）。cMT动态的实时成像显示，ABS6和SAV4都是cMT切断的正调节因子。此外，ABS6直接与KTN1和SAV4相互作用，促进它们向cMTs的募集。最后，对功能缺失突变体组合的分析表明，ABS6、SAV4和KTN1共同作用，确保了暗生长幼苗顶钩对乙烯的强烈响应。总之，我们的研究结果证实了ABS6和SAV4是cMT切断和排序的积极调节因子，并强调了cMT动态在微调植物差异生长中的作用。
Plant interphase cortical microtubules (cMTs) mediate anisotropic cell expansion in response to environmental and developmental cues. InArabidopsis thaliana, KATANIN 1 (KTN1), the p60 catalytic subunit of the conserved MT-severing enzyme katanin, is essential for cMT ordering and anisotropic cell expansion. However, the regulation of KTN1-mediated cMT severing and ordering remains unclear. In this work, we report that theArabidopsisIQ67 DOMAIN (IQD) family geneABNORMAL SHOOT 6(ABS6) encodes a MT-associated protein. Overexpression ofABS6leads to elongated cotyledons, directional pavement cell expansion, and highly ordered transverse cMT arrays. Genetic suppressor analysis revealed that ABS6-mediated cMT ordering is dependent on KTN1 and SHADE AVOIDANCE 4 (SAV4). Live imaging of cMT dynamics showed that both ABS6 and SAV4 function as positive regulators of cMT severing. Furthermore, ABS6 directly interacts with KTN1 and SAV4 and promotes their recruitment to the cMTs. Finally, analysis of loss-of-function mutant combinations showed that ABS6, SAV4, and KTN1 work together to ensure the robust ethylene response in the apical hook of dark-grown seedlings. Together, our findings establish ABS6 and SAV4 as positive regulators of cMT severing and ordering, and highlight the role of cMT dynamics in fine-tuning differential growth in plants.