Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, College of Horticulture Science, Zhejiang A&F University, Hangzhou, 311300, Zhejiang, China.
College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China.
BMC Plant Biol. 2023 Oct 11;23(1):484. doi: 10.1186/s12870-023-04438-x.
Light-harvesting chlorophyll a/b b evelopment of higher plants and in response to abiotic stress. Previous works has demonstrated that that Lhcb genes were involved in the phytochrome regulation and responded to the different light and temperature conditions in Poaceae (such as maize). However, the evolution and functions of Lhcb genes remains poorly characterized in important Rosaceae species.
In this investigation, we conducted a genome-wide analysis and identified a total of 212 Lhcb genes across nine Rosaceae species. Specifically, we found 23 Lhcb genes in Fragaria vesca, 20 in Prunus armeniaca, 33 in Malus domestica 'Gala', 21 in Prunus persica, 33 in Rosa chinensis, 29 in Pyrus bretschneideri, 18 in Rubus occidentalis, 20 in Prunus mume, and 15 in Prunus salicina. Phylogenetic analysis revealed that the Lhcb gene family could be classified into seven major subfamilies, with members of each subfamily sharing similar conserved motifs. And, the functions of each subfamily was predicted based on the previous reports from other species. The Lhcb proteins were highly conserved within their respective subfamilies, suggesting similar functions. Interestingly, we observed similar peaks in Ks values (0.1-0.2) for Lhcb genes in apple and pear, indicating a recent whole genome duplication event (about 30 to 45 million years ago). Additionally, a few Lhcb genes underwent tandem duplication and were located across all chromosomes of nine species of Rosaceae. Furthermore, the analysis of the cis-acting elements in the 2000 bp promoter region upstream of the pear Lhcb gene revealed four main categories: light response correlation, stress response correlation, hormone response correlation, and plant growth. Quantitative expression analysis demonstrated that Lhcb genes exhibited tissue-specific expression patterns and responded differently to low-temperature stress in Rosaceae species.
These findings shed light on the evolution and phylogeny of Lhcb genes in Rosaceae and highlight the critical role of Lhcb in pear's response to low temperatures. The results obtained provide valuable insights for further investigations into the functions of Lhcb genes in Rosaceae, and these functional genes will be used for further fruit tree breeding and improvement to cope with the current climate changes.
高等植物的光捕获叶绿素 a/b 蛋白的发展以及对非生物胁迫的响应。先前的研究表明，Lhcb 基因参与了光敏色素的调节，并对禾本科植物（如玉米）的不同光照和温度条件做出响应。然而，Lhcb 基因在重要蔷薇科物种中的进化和功能仍知之甚少。
在本研究中，我们对 9 种蔷薇科物种进行了全基因组分析，共鉴定出 212 个 Lhcb 基因。具体来说，我们在草莓中发现了 23 个 Lhcb 基因，在杏中发现了 20 个，在苹果中发现了 33 个，在桃中发现了 21 个，在月季花中发现了 33 个，在梨中发现了 29 个，在悬钩子中发现了 18 个，在梅花中发现了 20 个，在李中发现了 15 个。系统发育分析表明，Lhcb 基因家族可分为 7 个主要亚家族，每个亚家族的成员共享相似的保守基序。并且，根据其他物种的先前报道，预测了每个亚家族的功能。Lhcb 蛋白在各自的亚家族内高度保守，表明具有相似的功能。有趣的是，我们观察到苹果和梨的 Lhcb 基因的 Ks 值（0.1-0.2）相似，表明最近发生了全基因组复制事件（约 3000 万至 4500 万年前）。此外，一些 Lhcb 基因经历了串联重复，位于蔷薇科 9 个物种的所有染色体上。此外，对梨 Lhcb 基因上游 2000bp 启动子区域的顺式作用元件进行分析，发现了 4 个主要类别：光反应相关性、应激反应相关性、激素反应相关性和植物生长。定量表达分析表明，Lhcb 基因在蔷薇科物种中表现出组织特异性表达模式，并对低温胁迫有不同的反应。
这些发现揭示了蔷薇科 Lhcb 基因的进化和系统发育，并强调了 Lhcb 在梨对低温响应中的关键作用。研究结果为进一步研究 Lhcb 基因在蔷薇科中的功能提供了有价值的见解，这些功能基因将用于进一步的果树育种和改良，以应对当前的气候变化。
