Shuo Han, Xiaowen Han, Lu Hou, Junliang Yin
Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education/MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province) /Hubei Engineering Research Center for Pest Forewarning and Management/College of Agriculture, Yangtze University, Jingzhou 434025, Hubei, China.
Qinghai Academy of Agriculture and Forestry Science, Qinghai University/Key Laboratory of Agricultural Integrated Pest Management, Qinghai Province/State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining 810016, China.
Int J Biol Macromol. 2024 Dec;282(Pt 6):137548. doi: 10.1016/j.ijbiomac.2024.137548. Epub 2024 Nov 12.
The light-harvesting chlorophyll a/b-binding proteins (Lhcs) are integral to plants' capture and transfer of light energy during photosynthesis. However, the Lhc gene family remains unexplored in pepper. In this study, 37 CaLhcs (Capsicum annuum Lhc) were identified from the reference genome and classified into five subfamilies (Lhca, Lhcb, CP24, CP26, and CP29) based on phylogenetic relationships and conserved domains, with members of each subfamily displaying similar conserved motifs and gene structures. Cis-element analysis revealed an enrichment of light-responsive elements within CaLhcs (46.1%). Transcriptome analysis showed that most CaLhcs are specifically expressed in leaves, flowers, and pericarp and are responsive to stressors, including NaCl, cold, heat, HO, and d-mannitol. Post-transcriptional regulation analysis identified 11 miRNAs that target nine CaLhcs through cleavage. RT-qPCR analysis validated the involvement of CaLhcs in response to NaCl stress. Localization studies confirmed that CaLhca4.1, CaLhcb1.1, CaLhca1.7, CaLhcb1.11, and CaLhcb6.1 are chloroplast-localized, whereas CaLhca5.1 localizes in the nucleus. Overexpression of CaLhcb1.7 and CaLhca5.1 increased chlorophyll content and net photosynthetic rate, enhancing photosynthesis. Additionally, CaLhcb1.7 and CaLhca5.1 reduced ROS accumulation, bolstering the plant's resistance to pathogens and salt stress. These findings provide a foundation for further exploration of CaLhcs in photosynthesis and stress tolerance mechanisms.
捕光叶绿素a/b结合蛋白（Lhcs）在植物光合作用过程中对光能的捕获和传递至关重要。然而，辣椒中的Lhc基因家族尚未得到研究。在本研究中，从参考基因组中鉴定出37个CaLhcs（辣椒Lhc），并根据系统发育关系和保守结构域将其分为五个亚家族（Lhca、Lhcb、CP24、CP26和CP29），每个亚家族的成员具有相似的保守基序和基因结构。顺式作用元件分析显示CaLhcs中光响应元件富集（46.1%）。转录组分析表明，大多数CaLhcs在叶片、花朵和果皮中特异性表达，并对包括NaCl、冷、热、H₂O₂和D-甘露醇在内的应激源有反应。转录后调控分析鉴定出11个通过切割靶向9个CaLhcs的miRNA。RT-qPCR分析验证了CaLhcs参与对NaCl胁迫的响应。定位研究证实CaLhca4.1、CaLhcb1.1、CaLhca1.7、CaLhcb1.11和CaLhcb6.1定位于叶绿体，而CaLhca5.1定位于细胞核。CaLhcb1.7和CaLhca5.1的过表达增加了叶绿素含量和净光合速率，增强了光合作用。此外，CaLhcb1.7和CaLhca5.1减少了活性氧积累，增强了植物对病原体和盐胁迫的抗性。这些发现为进一步探索CaLhcs在光合作用和胁迫耐受机制中的作用提供了基础。
