Scholarlink

<p>The light-harvesting chlorophyll a/b-binding protein (LHC) superfamily plays a central role in optimizing photosynthetic efficiency and mediating abiotic stress responses in plants. However, its composition and function remain uncharacterized in <i>Hevea brasiliensis</i>, a key species for natural rubber production and tropical silviculture. Here, we present a comprehensive genome-wide identification and analysis of 43 <i>HbLHC</i> genes distributed across 15 chromosomes. Phylogenomic, transcriptomic, and interactome analyses revealed their evolutionary diversification and functional specialization in balancing latex metabolism and cold tolerance. These genes were classified into six subfamilies (Lhca, Lhcb, SEP, FCII, OHP, and PsbS), exhibiting diverse exon–intron structures (1–10 exons) and predicted subcellular localizations. Experimental validation confirmed chloroplast localization of HbLhcb2.2 and cytoplasmic accumulation of HbELIP, indicating neofunctionalization beyond canonical chloroplast roles. Tissue-specific expression profiling showed that <i>HbLhca3</i> is predominantly expressed in reproductive tissues (flowers/fruits), while <i>HbELIP</i> is highly expressed in latex-producing laticifers. Under cold stress (18&#xa0;°C/14°C, day/night), 34 <i>HbLHC</i> genes were significantly downregulated, coinciding with reduced PSII photoprotection via repression of the PsbS–STN7 module. Protein–protein interaction networks demonstrated evolutionary conservation in photosystem assembly, including HbLhca1–PSI–LHCI and HbLhcb4–PSII supercomplex associations. Notably, phased induction of <i>HbFCII1/2/3</i> and delayed upregulation of <i>HbPsb28</i> (3.1-fold at Day 7) highlighted hierarchical cold-responsive dynamics. Among these, HbPsbS and HbFCII1 emerged as key regulatory nodes stabilizing the photosynthetic apparatus under chilling conditions.&#xa0;This first genome-scale characterization of the LHC gene family in <i>H. brasiliensis</i> provides a molecular framework for improving cold tolerance through targeted manipulation of photosynthesis–stress crosstalk, thereby supporting climate-resilient rubber cultivation in subtropical regions.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Genome-wide characterization and expression analysis of the LHC gene family of Hevea Brasiliensis and its response to cold stress

  • 期刊论文

  • 发表日期：

    2025年10月4日

查看全文
  • Aifang Li,
  • Yang Yang,
  • Shaoli Tan,
  • Fengyan FangGebali,
  • Mei Wang,
  • Yuxin Li,
  • Mingwei Yao,
  • Xuchu Wang

摘要

The light-harvesting chlorophyll a/b-binding protein (LHC) superfamily plays a central role in optimizing photosynthetic efficiency and mediating abiotic stress responses in plants. However, its composition and function remain uncharacterized in Hevea brasiliensis, a key species for natural rubber production and tropical silviculture. Here, we present a comprehensive genome-wide identification and analysis of 43 HbLHC genes distributed across 15 chromosomes. Phylogenomic, transcriptomic, and interactome analyses revealed their evolutionary diversification and functional specialization in balancing latex metabolism and cold tolerance. These genes were classified into six subfamilies (Lhca, Lhcb, SEP, FCII, OHP, and PsbS), exhibiting diverse exon–intron structures (1–10 exons) and predicted subcellular localizations. Experimental validation confirmed chloroplast localization of HbLhcb2.2 and cytoplasmic accumulation of HbELIP, indicating neofunctionalization beyond canonical chloroplast roles. Tissue-specific expression profiling showed that HbLhca3 is predominantly expressed in reproductive tissues (flowers/fruits), while HbELIP is highly expressed in latex-producing laticifers. Under cold stress (18 °C/14°C, day/night), 34 HbLHC genes were significantly downregulated, coinciding with reduced PSII photoprotection via repression of the PsbS–STN7 module. Protein–protein interaction networks demonstrated evolutionary conservation in photosystem assembly, including HbLhca1–PSI–LHCI and HbLhcb4–PSII supercomplex associations. Notably, phased induction of HbFCII1/2/3 and delayed upregulation of HbPsb28 (3.1-fold at Day 7) highlighted hierarchical cold-responsive dynamics. Among these, HbPsbS and HbFCII1 emerged as key regulatory nodes stabilizing the photosynthetic apparatus under chilling conditions. This first genome-scale characterization of the LHC gene family in H. brasiliensis provides a molecular framework for improving cold tolerance through targeted manipulation of photosynthesis–stress crosstalk, thereby supporting climate-resilient rubber cultivation in subtropical regions.