AUTHOR=Rajasheker Guddimalli , Nagaraju Marka , Varghese Rinku Polachirakkal , Jalaja Naravula , Somanaboina Anil Kumar , Singam Prashant , Ramakrishna Chintala , Penna Suprasanna , Sreenivasulu Nese , Kishor P. B. Kavi 

TITLE=Identification and analysis of proline-rich proteins and hybrid proline-rich proteins super family genes from Sorghum bicolor and their expression patterns to abiotic stress and zinc stimuli

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.952732

DOI=10.3389/fpls.2022.952732

ISSN=1664-462X

ABSTRACT=<p>Systematic genome-wide analysis of <italic>Sorghum bicolor</italic> revealed the identification of a total of 48 homologous genes comprising 21 proline-rich proteins (<italic>PRPs</italic>) and 27 hybrid proline-rich proteins (<italic>HyPRPs</italic>). Comprehensive scrutiny of these gene homologs was conducted for gene structure, phylogenetic investigations, chromosome mapping, and subcellular localization of proteins. Promoter analysis uncovered the regions rich with phosphorous- (BIHD), ammonium-, sulfur-responsive (SURE), and iron starvation-responsive (IRO2) along with biotic, abiotic, and development-specific <italic>cis</italic>-elements. Further, PRPs exhibit more methylation and acetylation sites in comparison with HyPRPs. miRNAs have been predicted which might play a role in cleavage and translation inhibition. Several of the <italic>SbPRP</italic> genes were stimulated in a tissue-specific manner under drought, salt, heat, and cold stresses. Additionally, exposure of plants to abscisic acid (ABA) and zinc (Zn) also triggered PRP genes in a tissue-dependent way. Among them, <italic>SbPRP17</italic> has been found upregulated markedly in all tissues irrespective of the stress imposed. The expressions of <italic>SbHyPRPs</italic>, especially <italic>SbHyPRP2</italic>, <italic>SbHyPRP6</italic>, and <italic>SbHyPRP17</italic> were activated under all stresses in all three tissues. On the other hand, <italic>SbHyPRP8</italic> (root only) and <italic>SbHyPRP12</italic> (all three tissues) were highly responsive to cold stress and ABA while <italic>SbHyPRP26</italic> was induced by drought and Zn in the stem. Taken together, this study indicates the critical roles that <italic>SbPRPs</italic> and <italic>SbHyPRPs</italic> play during diverse abiotic stress conditions and notably the plausible roles that these genes play upon exposure to zinc, the crucial micronutrient in plants.</p>