CaBBX9作为自噬调节蛋白CaATG8c的相互作用伴侣，
对辣椒的耐热性具有负调控作用

doi:10.1016/j.jia.2025.03.022

摘要/Abstract

摘要：

为了探索自噬对辣椒耐热性贡献的分子机制，在之前的研究中，我们鉴定了锌指蛋白B-BOX 9/CONSTANS-LIKE 13（CaBBX9/CaCOL13）作为自噬调节蛋白（ATG）CaATG8c的相互作用伴侣，其中CaATG8c是自噬的核心组分之一。然而，CaBBX9在自噬和耐热性中的作用尚不清楚。在这项研究中，我们进一步证实了CaBBX9与CaATG8c之间的相互作用，并定义了CaBBX9的相互作用区域是CCT结构域以及特定片段区域。热处理可以诱导CaBBX9的表达，并发现CaBBX9与CaATG8c在细胞核中共定位且表现出转录活性。当沉默CaBBX9时，辣椒的耐热性增强，表现为MDA含量、H2O2、死细胞和相对电解质渗漏的减少以及叶绿素含量和热胁迫相关基因表达水平的增加。在番茄中过表达CaBBX9则显示出相反的效果。综上所述，我们的研究表明，CaBBX9通过加剧氧化损伤和抑制热相关基因的表达来负向调节辣椒的耐热性。我们的发现为指导作物对不利环境的耐受性育种提供了新的线索。

Abstract:

In order to explore the molecular mechanisms underlying the contribution of autophagy to pepper’s heat tolerance, in previous study, we identified the zinc-finger protein B-BOX 9/CONSTANS-LIKE 13 (CaBBX9/CaCOL13) as an interaction partner of Autophagy regulated protein (ATG) CaATG8c, one of the core components in autophagy. However, the involvements of CaBBX9 in both autophagy and heat tolerance remain unclear. In this study, we further confirmed the interaction between CaBBX9 with CaATG8c, and defined the interaction regions of CaBBX9 are CONSTANS, CONSTANS-Like and TOC1 (CCT) domain and the fragment region. The expression of CaBBX9 can be induced by heat treatment. CaBBX9 is co-localized with CaATG8c in the nucleus and exhibits a transcriptional activity. When the expression of CaBBX9 is silenced, the heat-tolerance of pepper is enhanced, shown by the decrement of MDA content, H₂O₂, dead cells, and relative electrolyte leakage, and the increment of chlorophyll content and expression level of heat stress related genes. Overexpression of CaBBX9 in tomatoes displays the opposite effects. Taken together, our study demonstrates that CaBBX9 negatively regulates the heat-tolerance of peppers by exacerbating oxidative damage and inhibiting the expression of heat related genes. Our findings provide a new clue for guiding crop breeding for tolerance to adverse environment.

Key words: pepper , CaBBX9 , , CaATG8c , , Heat tolerance , , Autophagy

. CaBBX9作为自噬调节蛋白CaATG8c的相互作用伴侣，对辣椒的耐热性具有负调控作用[J]. Journal of Integrative Agriculture, DOI: 10.1016/j.jia.2025.03.022.

Li Zhang, Yuling Guo, Sitian Wang, Zhenze Wang, Qiaomin Yang, Ying Li, Yue Zhao, Haiyan Li, Lijun Cao, Minghui Lu. CaBBX9, an interaction partner of autophagy regulated protein CaATG8c, negatively regulates heat tolerance of pepper[J]. Journal of Integrative Agriculture, DOI: 10.1016/j.jia.2025.03.022.

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