A poplar B-box protein PtrBBX23 modulates the accumulation of anthocyanins and proanthocyanidins in response to high light
A poplar B-box protein PtrBBX23 modulates the accumulation of anthocyanins and proanthocyanidins in response to high light
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DOI：
10.1111/pce.14127
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发表时间：
2021-06-17
影响因子：
7.3
通讯作者：
Lian, Chunlan
中科院分区：
文献类型：
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作者：
Li, Chaofeng;Pei, Jinli;Lian, Chunlan
强光可诱导植物产生黄光，黄光可调节植物对各种逆境的抗性。B-box（BBX）转录因子（TF）在类黄酮生物合成的转录调控中起着至关重要的作用，但关于BBX蛋白与强光的关系的信息有限。我们提出了一个详细的概述45胡杨BBX TF。在10种胁迫或植物激素处理下确定了系统发育关系、基因结构、组织特异性表达模式和表达谱，以筛选与类黄酮途径相关的候选BBX蛋白。共鉴定出16个候选基因，其中5个主要在幼叶和根中表达，BBX 23对强光的反应最明显。BBX 23在白杨中的过表达激活了MYB转录因子和类黄酮途径中的结构基因的表达，从而促进了原花青素和花青素的积累。CRISPR/Cas9产生的BBX 23敲除导致相反的趋势。此外，BBX 23过表达诱导的表型在强光下增强。BBX 23能够直接与原花青素和花青素特异性基因的启动子结合，并且其与HY 5的相互作用增强了激活活性。我们确定了白杨类黄酮生物合成的新调控因子，从而提高了我们对所涉及的转录调控机制的总体理解。
Flavonoids, which modulate plant resistance to various stresses, can be induced by high light. B-box (BBX) transcription factors (TFs) play crucial roles in the transcriptional regulation of flavonoids biosynthesis, but limited information is available on the association of BBX proteins with high light. We present a detailed overview of 45 Populus trichocarpa BBX TFs. Phylogenetic relationships, gene structure, tissuespecific expression patterns and expression profiles were determined under 10 stress or phytohormone treatments to screen candidate BBX proteins associated with the flavonoid pathway. Sixteen candidate genes were identified, of which five were expressed predominantly in young leaves and roots, and BBX23 showed the most distinct response to high light. Overexpression of BBX23 in poplar activated expression of MYB TFs and structural genes in the flavonoid pathway, thereby promoting the accumulation of proanthocyanidins and anthocyanins. CRISPR/Cas9-generated knockout of BBX23 resulted in the opposite trend. Furthermore, the phenotype induced by BBX23 overexpression was enhanced under exposure to high light. BBX23 was capable of binding directly to the promoters of proanthocyanidin- and anthocyanin-specific genes, and its interaction with HY5 enhanced activation activity. We identified novel regulators of flavonoid biosynthesis in poplar, thereby enhancing our general understanding of the transcriptional regulatory mechanisms involved.