Department of Genetics, Osmania University, Hyderabad, India.
Department of Biotechnology, Vignan's Foundation for Science, Technology and Research, Vadlamudi, Guntur, Andhra Pradesh, India.
PLoS One. 2019 Jan 16;14(1):e0209980. doi: 10.1371/journal.pone.0209980. eCollection 2019.
Late embryogenesis abundant (LEA) proteins, the space fillers or molecular shields, are the hydrophilic protective proteins which play an important role during plant development and abiotic stress. The systematic survey and characterization revealed a total of 68 LEA genes, belonging to 8 families in Sorghum bicolor. The LEA-2, a typical hydrophobic family is the most abundant family. All of them are evenly distributed on all 10 chromosomes and chromosomes 1, 2, and 3 appear to be the hot spots. Majority of the S. bicolor LEA (SbLEA) genes are intron less or have fewer introns. A total of 22 paralogous events were observed and majority of them appear to be segmental duplications. Segmental duplication played an important role in SbLEA-2 family expansion. A total of 12 orthologs were observed with Arabidopsis and 13 with Oryza sativa. Majority of them are basic in nature, and targeted by chloroplast subcellular localization. Fifteen miRNAs targeted to 25 SbLEAs appear to participate in development, as well as in abiotic stress tolerance. Promoter analysis revealed the presence of abiotic stress-responsive DRE, MYB, MYC, and GT1, biotic stress-responsive W-Box, hormone-responsive ABA, ERE, and TGA, and development-responsive SKn cis-elements. This reveals that LEA proteins play a vital role during stress tolerance and developmental processes. Using microarray data, 65 SbLEA genes were analyzed in different tissues (roots, pith, rind, internode, shoot, and leaf) which show clear tissue specific expression. qRT-PCR analysis of 23 SbLEA genes revealed their abundant expression in various tissues like roots, stems and leaves. Higher expression was noticed in stems compared to roots and leaves. Majority of the SbLEA family members were up-regulated at least in one tissue under different stress conditions. The SbLEA3-2 is the regulator, which showed abundant expression under diverse stress conditions. Present study provides new insights into the formation of LEAs in S. bicolor and to understand their role in developmental processes under stress conditions, which may be a valuable source for future research.
晚期胚胎丰富（LEA）蛋白是亲水性保护蛋白，作为空间填充物或分子盾牌，在植物发育和非生物胁迫中发挥重要作用。系统调查和特征分析表明，在高粱中共有 68 个 LEA 基因，属于 8 个家族。LEA-2 是一种典型的疏水性家族，是最丰富的家族。它们都均匀地分布在所有 10 条染色体上，染色体 1、2 和 3 似乎是热点。高粱的大多数 LEA（SbLEA）基因没有内含子或只有少数内含子。总共观察到 22 个旁系同源事件，其中大多数似乎是片段重复。片段重复在 SbLEA-2 家族的扩张中起着重要作用。总共观察到 12 个与拟南芥的同源物和 13 个与水稻的同源物。它们大多数是碱性的，靶向叶绿体亚细胞定位。有 15 个 miRNA 靶向 25 个 SbLEAs，似乎参与发育以及非生物胁迫耐受性。启动子分析表明，存在非生物胁迫响应 DRE、MYB、MYC 和 GT1、生物胁迫响应 W-Box、激素响应 ABA、ERE 和 TGA，以及发育响应 SKn 顺式元件。这表明 LEA 蛋白在胁迫耐受性和发育过程中起着至关重要的作用。利用微阵列数据，对不同组织（根、髓、皮、节间、茎和叶）中的 65 个 SbLEA 基因进行了分析，结果显示其具有明显的组织特异性表达。对 23 个 SbLEA 基因的 qRT-PCR 分析表明，它们在根、茎和叶等各种组织中大量表达。与根和叶相比，茎中的表达更高。在不同胁迫条件下，大多数 SbLEA 家族成员至少在一种组织中上调。SbLEA3-2 是调节剂，在不同胁迫条件下均有大量表达。本研究为高粱 LEA 的形成提供了新的见解，并有助于理解它们在胁迫条件下发育过程中的作用，这可能是未来研究的宝贵资源。
