Department of Plant Breeding and Genetics, University of Agriculture Faisalabad, Faisalabad 38040, Pakistan.
State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Research Center of Perennial Rice Engineering and Technology in Yunnan, School of Agriculture, Yunnan University, Kunming 650500, China; Industrial Crops Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650200, China; Department of Bioinformatics and Biotechnology, Government College University, Faisalabad 38000, Pakistan.
Genomics. 2021 Jan;113(1 Pt 2):1029-1043. doi: 10.1016/j.ygeno.2020.10.037. Epub 2020 Nov 4.
Rice is an important cereal crop that serves as staple food for more than half of the world population. Abiotic stresses resulting from changing climatic conditions are continuously threating its yield and production. Genes in APETALA-2 (AP2) family encode transcriptional regulators implicated during regulation of developmental processes and abiotic stress responses but their identification and characterization in indica rice was still missing. In this context, twenty-six genes distributed among eleven chromosomes in Indica rice encoding AP2 transcription-factor subfamily were identified and their diverse haplotypes were studied. Phylogenetic analysis of OsAP2 TF family-members grouped them into three clades indicating conservation of clades among cereals. Segmental duplications were observed to be principal route of evolution, supporting the higher positive selection-pressure, which were estimated to be originated about 10.57 to 56.72 million years ago (MYA). Conserved domain analysis and intron-exon distribution pattern of identified OsAP2s revealed their exclusive distribution among the specific clades of the phylogenetic tree. Moreover, the members of osa-miR172 family were also identified potentially targeting four OsAP2 genes. The real-time quantitative expression profiling of OsAP2s under heat stress conditions in contrasting indica rice genotypes revealed the differential expression pattern of OsAP2s (6 genes up-regulated and 4 genes down-regulated) in stress- and genotype-dependent manner. These findings unveiled the evolutionary pathways of AP2-TF in rice, and can help the functional characterization under developmental and stress responses.
水稻是一种重要的谷类作物，是全球一半以上人口的主食。由于气候变化导致的非生物胁迫不断威胁着其产量和生产。AP2 家族的基因编码参与发育过程和非生物胁迫反应调节的转录因子，但它们在籼稻中的鉴定和特征仍然缺失。在这种情况下，鉴定了 26 个分布在籼稻 11 条染色体上的编码 AP2 转录因子亚家族的基因，并研究了它们的多种单倍型。对 OsAP2 TF 家族成员的系统发育分析将它们分为三个分支，表明分支在谷物中是保守的。片段重复被认为是进化的主要途径，支持更高的正选择压力，这被估计是在大约 1057 到 5672 万年前起源的。保守结构域分析和鉴定的 OsAP2 的内含子-外显子分布模式揭示了它们在系统发育树的特定分支中的独特分布。此外，还鉴定了 osa-miR172 家族的成员，它们可能靶向 4 个 OsAP2 基因。在不同的籼稻基因型中，对 OsAP2 在热胁迫条件下的实时定量表达谱进行分析，结果表明 OsAP2 的表达模式（6 个上调基因和 4 个下调基因）在胁迫和基因型依赖性方式下存在差异。这些发现揭示了水稻中 AP2-TF 的进化途径，并有助于在发育和应激反应下进行功能特征分析。
