The B-box protein BBX19 suppresses seed germination via induction of ABI5
The B-box protein BBX19 suppresses seed germination via induction of ABI5
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B-box 蛋白 BBX19 通过诱导 ABI5 抑制种子萌发
DOI：
10.1111/tpj.14415
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发表时间：
2019-09-01
期刊：
影响因子：
7.2
通讯作者：
Dehesh, Katayoon
中科院分区：
文献类型：
--
作者：
Bai, Mengjuan;Sun, Jingjing;Dehesh, Katayoon
种子萌发是植物生活史中的一个基本过程，受功能上相反的内部和外部输入的调节。在这里，我们探索了光形态建成的负调控蛋白-B盒蛋白(BBX19)作为植物激素脱落酸(ABA)抑制作用和光在萌发中促进作用之间的分子联系。我们发现，与BBX19 RNA干扰系相比，BBX19高表达系的种子表现出ABA超敏反应，尽管独立于延长的下胚轴5(HY5)。此外，我们证实BBX19既不是通过干扰GA信号，即ABA拮抗植物激素，也不是通过干扰Della蛋白萌发抑制因子发挥作用。相反，BBX19通过与基因启动子中的光响应GT1基序结合而起到ABA INSENSITIVE5(ABI5)的诱导剂的作用。综上所述，我们将BBX19确定为一个调节检查点，指导不同的发育过程，并根据不同的内源和外源信号定制适应性反应。
Seed germination is a fundamental process in the plant life cycle and is regulated by functionally opposing internal and external inputs. Here we explored the role of a negative regulator of photomorphogenesis, a B-box-containing protein (BBX19), as a molecular link between the inhibitory action of the phytohormone abscisic acid (ABA) and the promoting role of light in germination. We show that seeds of BBX19-overexpressing lines, in contrast to those of BBX19 RNA interference lines, display ABA hypersensitivity, albeit independently of elongated hypocotyl 5 (HY5). Moreover, we establish that BBX19 functions neither via perturbation of GA signaling, the ABA antagonistic phytohormone, nor through interference with the DELLA protein germination repressors. Rather, BBX19 functions as an inducer of ABA INSENSITIVE5 (ABI5) by binding to the light-responsive GT1 motifs in the gene promoter. In summary, we identify BBX19 as a regulatory checkpoint, directing diverse developmental processes and tailoring adaptive responses to distinct endogenous and exogenous signals.