Identification of Histone H3 (<i>HH3</i>) Genes in <i>Gossypium hirsutum</i> Revealed Diverse Expression During Ovule Development and Stress Responses

• Main Authors: Ghulam Qanmber, Faiza Ali, Lili Lu, Huijuan Mo, Shuya Ma, Zhi Wang, Zuoren Yang
• Format: Article
• Language: English
• Published: MDPI AG 2019-05-01
• Series: Genes
• Subjects: <i>Gossypium hirsutum</i>; <i>GhHH3</i>; phylogenetic analysis; gene duplication; cis-elements; expression pattern; abiotic stress; phytohormonal stress
• Online Access: https://www.mdpi.com/2073-4425/10/5/355

Histone acts as the core for nucleosomes and is a key protein component of chromatin. Among different histone variants, histone H3 (HH3) variants have been reported to play vital roles in plant development. However, biological information and evolutionary relationships of <i>HH3</i> genes in cotton remain to be elucidated. The current study identified 34 <i>HH3</i> genes in <i>Gossypium hirsutum</i>. Phylogenetic analysis classified <i>HH3</i> genes of 19 plant species into eight distinct clades. Sequence logos analysis among <i>Arabidopsis</i>, rice, and <i>G. hirsutum</i> amino acid residues showed higher conservation in amino acids. Using collinearity analysis, we identified 81 orthologous/paralogous gene pairs among the four genomes (A, D, At, and Dt) of cotton. Further, orthologous/paralogous and the Ka/Ks ratio demonstrated that cotton <i>HH3</i> genes experienced strong purifying selection pressure with restricted functional divergence resulting from segmental and whole genome duplication. Expression pattern analysis indicated that <i>GhHH3</i> genes were preferentially expressed in cotton ovule tissues. Additionally, <i>GhHH3</i> gene expression can be regulated by abiotic stresses (cold, heat, sodium chloride (NaCl), and polyethylene glycol (PEG)) and phytohormonal (brassinolide (BL), gibberellic acid (GA), indole-3-acetic acid (IAA), salicylic acid (SA), and methyl jasmonate (MeJA)) treatments, suggesting that <i>GhHH3</i> genes might play roles in abiotic and hormone stress resistance. Taken together, this work provides important information to decipher complete molecular and physiological functions of <i>HH3</i> genes in cotton.