Crosstalk between the cytokinin and MAX2 signaling pathways in growth and callus formation of Arabidopsis thaliana
Crosstalk between the cytokinin and MAX2 signaling pathways in growth and callus formation of Arabidopsis thaliana
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DOI：
10.1016/j.bbrc.2019.02.038
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发表时间：
2019-04-02
影响因子：
3.1
通讯作者：
Lam-Son Phan Tran
中科院分区：
文献类型：
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作者：
Li, Weiqiang;Kien Huu Nguyen;Lam-Son Phan Tran
细胞分裂素（CK）信号转导在愈伤组织的形成和多种发育过程中起着重要的作用，通过分析不同的CK应答突变体，包括ahk 2 ahk 3（AHK，拟南芥组氨酸激酶）双突变体。最近，一个F盒蛋白，称为MAX2（更多腋窝生长2）被确定为一个关键组成部分，通过独脚金内酯和/或karrikin途径调节许多生长和发育过程。然而，MAX2信号在愈伤组织形成、种子大小和产量中的功能，以及其与CK信号的相互作用对植物生长发育的影响仍然是未知的。在此，我们构建了三突变体ahk 2 ahk 3 max 2，并分析了所有三个max 2、ahk 2 ahk 3和ahk 2 ahk 3 max 2突变体沿着与野生型（WT）在植物生长发育过程中的愈伤组织形成和各种表型性状。我们发现，MAX 2作为种子大小的负调节剂，但正调节愈伤组织的形成和种子产量，虽然在较低程度上，作为CK受体激酶。重要的是，我们的比较分析揭示了CK和MAX2途径对主根生长，下胚轴伸长和芽分枝的相互作用。然而，这两条途径可能独立地调节根毛生长、叶片发育、叶片衰老、株高、种子大小、种子产量和愈伤组织形成。我们的研究结果不仅提供了MAX2参与调节愈伤组织形成，种子大小和种子产量的证据，而且还更好地了解CK和MAX2信号通路在植物生命中许多关键发育过程中的关系。(C)2019爱思唯尔公司All rights reserved.
Cytokinin (CK) signaling has been shown to play important roles in callus formation and various developmental processes by analyzing different CK-responsive mutants, including the ahk2 ahk3 (AHK, Arabidopsis histidine kinase) double mutant. Recently, an F-box protein, called MAX2 (more axillary growth 2) was identified as a key component regulating many growth and developmental processes through the strigolactone and/or karrikin pathways. However, the function of MAX2 signaling in callus formation, seed size and yield, as well as the effects of its crosstalk with CK signaling on plant growth and development remain elusive. Here, we constructed the triple mutant ahk2 ahk3 max2 and analyzed the callus formation and various phenotypic traits of all three max2, ahk2 ahk3 and ahk2 ahk3 max2 mutants along with wild-type (WT) during plant growth and development. We showed that MAX2 acted as a negative regulator of seed size, but positive regulator of callus formation and seed yield albeit at lower degree, as the CK receptor kinases. Importantly, our comparative analyses revealed interactive effects of CK and MAX2 pathways on primary root growth, hypocotyl elongation and shoot branching. However, these two pathways might independently regulate root hair growth, leaf development, leaf senescence, plant height, seed size, seed yield and callus formation. Our findings provide not only evidence for the involvement of MAX2 in regulating callus formation, seed size and seed yield, but also a better understanding of the relationship between CK and MAX2 signaling pathways in many key developmental processes across a plant's life. (C) 2019 Elsevier Inc. All rights reserved.