Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences/Hainan Key Laboratory of Tropical Oil Crops Biology, Wenchang 571300, China.
The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering and College of Life Sciences, Guizhou University, Guiyang 550025, China.
Int J Mol Sci. 2024 Sep 18;25(18):10048. doi: 10.3390/ijms251810048.
Abiotic stresses such as nitrogen deficiency, drought, and salinity significantly impact coconut production, yet the molecular mechanisms underlying coconut's response to these stresses are poorly understood. MYB proteins, a large and diverse family of transcription factors (TF), play crucial roles in plant responses to various abiotic stresses, but their genome-wide characterization and functional roles in coconut have not been comprehensively explored. This study identified 214 genes (39 1R-MYB, 171 R2R3-MYB, 2 3R-MYB, and 2 4R-MYB) in the coconut genome. Phylogenetic analysis revealed that these genes are unevenly distributed across the 16 chromosomes, with conserved consensus sequences, motifs, and gene structures within the same subgroups. Synteny analysis indicated that segmental duplication primarily drove evolution in coconut, with low nonsynonymous/synonymous ratios suggesting strong purifying selection. The gene ontology (GO) annotation of protein sequences provided insights into the biological functions of the gene family. and were identified as homologous genes linked to nitrogen deficiency, drought, and salinity stress through BLAST, highlighting the key role of CnMYB genes in abiotic stress tolerance. Quantitative analysis of PCR showed 10 genes in leaves and petioles and found that the expression of was higher in 3-month-old than one-year-old coconut, whereas was higher in one-year-old coconut. Moreover, the expression of , , and was high under nitrogen deficiency, drought, and salinity stress, respectively. The predicted secondary and tertiary structures of three key CnMYB proteins involved in abiotic stress revealed distinct inter-proteomic features. The predicted interaction between CnMYB2/158 and Hsp70 supports its role in coconut's drought and salinity stress responses. These results expand our understanding of the relationships between the evolution and function of genes, and provide valuable insights into the gene family's role in abiotic stress in coconut.
非生物胁迫，如氮缺乏、干旱和盐胁迫，严重影响椰子的生产，但椰子对这些胁迫的反应的分子机制还知之甚少。MYB 蛋白是一类庞大而多样的转录因子（TF），在植物对各种非生物胁迫的反应中起着至关重要的作用，但它们在椰子中的全基因组特征和功能作用尚未得到全面探索。本研究在椰子基因组中鉴定出 214 个基因（39 个 1R-MYB、171 个 R2R3-MYB、2 个 3R-MYB 和 2 个 4R-MYB）。系统发育分析表明，这些基因在 16 条染色体上不均匀分布，具有保守的共识序列、基序和同一亚组内的基因结构。共线性分析表明，片段复制主要驱动了椰子的进化，低非同义/同义比表明强烈的纯化选择。蛋白质序列的基因本体（GO）注释提供了对基因家族生物学功能的深入了解。通过 BLAST 鉴定出与氮缺乏、干旱和盐胁迫相关的同源基因 ，强调了 CnMYB 基因在非生物胁迫耐受中的关键作用。定量 PCR 分析显示，叶片和叶柄中有 10 个基因，发现 3 个月龄椰子的 表达高于 1 年椰子，而 1 年椰子的 表达较高。此外，在氮缺乏、干旱和盐胁迫下， 、 、 和 的表达水平较高。三个参与非生物胁迫的关键 CnMYB 蛋白的预测二级和三级结构揭示了不同的互蛋白质组特征。CnMYB2/158 与 Hsp70 之间的预测相互作用支持其在椰子干旱和盐胁迫反应中的作用。这些结果扩展了我们对 基因进化和功能关系的理解，并为 CnMYB 基因家族在椰子非生物胁迫中的作用提供了有价值的见解。
