The ABA receptor PYL9 together with PYL8 plays an important role in regulating lateral root growth.
The ABA receptor PYL9 together with PYL8 plays an important role in regulating lateral root growth.
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DOI：
10.1038/srep27177
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发表时间：
2016-06-03
影响因子：
4.6
通讯作者：
Zhu JK
中科院分区：
文献类型：
--
作者：
Xing L;Zhao Y;Gao J;Xiang C;Zhu JK
脱落酸是一种调节植物生长、发育和应激反应的植物激素。 PYR1/PYL/RCAR 蛋白是 ABA 受体，通过抑制 PP2C 激活 SnRK2 发挥作用，导致 ABF 和 ABA 响应途径的其他效应子磷酸化。外源 ABA 诱导侧根生长静止，通过敲除 ABA 受体 PYL8 延长这种静止状态。在PYR1/PYL/RCAR蛋白家族的14个成员中，PYL9是PYL8的近亲。在这里，我们发现，与单独敲除 PYL8 相比，敲除 PYL9 和 PYL8 会导致 ABA 诱导的侧根生长静止时间更长，并且对初生根生长和侧根形成的 ABA 敏感性降低。在 ABA 存在下，诱导 PYL9 过度表达可促进侧根伸长。 pyl8-1pyl9 双突变体的延长静止期可被外源 IAA 逆转。 PYL9 可能通过与 MYB77 和 MYB44 直接相互作用来调节体内生长素响应基因。因此，PYL9 和 PYL8 都负责通过 MYB 转录因子使侧根从 ABA 抑制中恢复。
Abscisic acid is a phytohormone regulating plant growth, development and stress responses. PYR1/PYL/RCAR proteins are ABA receptors that function by inhibiting PP2Cs to activate SnRK2s, resulting in phosphorylation of ABFs and other effectors of ABA response pathways. Exogenous ABA induces growth quiescence of lateral roots, which is prolonged by knockout of the ABA receptor PYL8. Among the 14 members of PYR1/PYL/RCAR protein family, PYL9 is a close relative of PYL8. Here we show that knockout of both PYL9 and PYL8 resulted in a longer ABA-induced quiescence on lateral root growth and a reduced sensitivity to ABA on primary root growth and lateral root formation compared to knockout of PYL8 alone. Induced overexpression of PYL9 promoted the lateral root elongation in the presence of ABA. The prolonged quiescent phase of the pyl8-1pyl9 double mutant was reversed by exogenous IAA. PYL9 may regulate auxin-responsive genes in vivo through direct interaction with MYB77 and MYB44. Thus, PYL9 and PYL8 are both responsible for recovery of lateral root from ABA inhibition via MYB transcription factors.