Li Chang, Ma Shengwei, Tian Yulong, Zheng Xiaojuan
Sanya Nanfan Research Institute, Hainan University, Sanya, China.
School of Tropical Agriculture and Forestry, Hainan University, Haikou, China.
Front Plant Sci. 2025 Sep 1;16:1577679. doi: 10.3389/fpls.2025.1577679. eCollection 2025.
Mihoutao () has significant nutritional and economic value, with China leading the world in both cultivation area and production volume. However, bacterial canker caused by Pseudomonas syringae pv. actinidiae () poses a devastating threat to the Mihoutao industry, severely affecting yields. The most effective strategy to combat this disease is through the breeding of resistant varieties. The leucine-rich repeat receptor-like kinase () family, a major subclass of plant receptor-like kinases, plays crucial roles in plant growth and stress regulation. However, research on genes in Mihoutao remains unexplored.
In this study, we performed a genome-wide identification of the gene family in cv. Hongyang (HY). Their phylogenetic relationships, gene structures, conserved motif, chromosomal location, gene duplication events and promoter cis-elements were analyzed. In addition, we analyzed the genes of the gene family that respond to infection based on transcriptomic data and verified their gene expression patterns by qRT-PCR.
n this study, we identified and manually corrected genes in two haplotypes of HY, resulting in a nonredundant set of 394 genes. Phylogenetic analysis revealed that these genes are classified into 21 subfamilies distributed across 29 chromosomes. Gene structure analysis revealed high diversity in the LRR domains of genes, while the kinase domains were relatively conserved. Analysis of cis-acting elements further suggested the involvement of genes in critical biological processes such as the light response, hormone response, growth and development, and biotic and abiotic stresses in HY. Furthermore, transcriptomic analysis across different tissues revealed that the majority of AcLRR-RLK genes play a role in five tissues: root, stem, leaf, flower, and fruit. Additionally, transcriptomic analysis under Psa infection indicated that, HY activated its defense response, with an increasing number of genes responding to pathogen invasion. Among these genes, 48 genes were identified as core genes responsive to , and genes from subgroup XII may play a critical role in the defense mechanism against pathogen invasion. Our study provides an in-depth investigation into the characteristics and functions of the gene family in A. chinensis, laying a molecular foundation for further disease-resistant and high quality breeding efforts.
猕猴桃具有重要的营养和经济价值，中国在其种植面积和产量方面均位居世界首位。然而，由丁香假单胞菌猕猴桃致病变种（Pseudomonas syringae pv. actinidiae）引起的细菌性溃疡病对猕猴桃产业构成了毁灭性威胁，严重影响产量。对抗这种疾病最有效的策略是培育抗性品种。富含亮氨酸重复序列的类受体激酶（leucine-rich repeat receptor-like kinase，LRR-RLK）家族是植物类受体激酶的一个主要亚类，在植物生长和胁迫调节中起关键作用。然而，关于猕猴桃中AcLRR-RLK基因的研究仍未开展。
在本研究中，我们对猕猴桃品种红阳（Hongyang，HY）中的AcLRR-RLK基因家族进行了全基因组鉴定。分析了它们的系统发育关系、基因结构、保守基序、染色体定位、基因复制事件和启动子顺式元件。此外，我们基于转录组数据分析了AcLRR-RLK基因家族中响应Psa感染的基因，并通过qRT-PCR验证了它们的基因表达模式。
在本研究中，我们在HY的两个单倍型中鉴定并手动校正了AcLRR-RLK基因，得到了一组394个非冗余的AcLRR-RLK基因。系统发育分析表明，这些AcLRR-RLK基因被分为21个亚家族，分布在29条染色体上。基因结构分析显示，AcLRR-RLK基因的LRR结构域具有高度多样性，而激酶结构域相对保守。顺式作用元件分析进一步表明，AcLRR-RLK基因参与了红阳猕猴桃的光响应、激素响应、生长发育以及生物和非生物胁迫等关键生物学过程。此外，对不同组织的转录组分析表明，大多数AcLRR-RLK基因在根、茎、叶、花和果实这五个组织中发挥作用。另外，Psa感染下的转录组分析表明，红阳猕猴桃激活了其防御反应，有越来越多的AcLRR-RLK基因对病原体入侵作出响应。在这些基因中，48个AcLRR-RLK基因被鉴定为对Psa响应的核心基因，并且来自第十二亚组的基因可能在抵御病原体入侵的防御机制中起关键作用。我们的研究深入调查了中华猕猴桃中AcLRR-RLK基因家族的特征和功能，为进一步的抗病和高品质育种工作奠定了分子基础。
