AUTHOR=Li Jianwei , Sun Mingzhe , Liu Yu , Sun Xiaoli , Yin Kuide 

TITLE=Genome-Wide Identification of Wild Soybean Mitochondrial Calcium Uniporter Family Genes and Their Responses to Cold and Carbonate Alkaline Stresses

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.867503

DOI=10.3389/fpls.2022.867503

ISSN=1664-462X

ABSTRACT=<p>The mitochondrial calcium uniporter (MCU), as an important component of the Ca<sup>2+</sup> channel uniporter complex, plays a regulatory role in intracellular Ca<sup>2+</sup> signal transduction. However, only a few studies to date have investigated plant MCU genes. In this study, we identified the MCU family genes in wild soybean and investigated their expression under cold and carbonate alkaline stresses. Eleven <italic>Glycine soja</italic> MCU genes (<italic>GsMCUs</italic>) were identified and clustered into two subgroups (subgroups I and II), and subgroup II could be further divided into two branches (MCU5 and MCU6). A total of 21 pairs of <italic>GsMCUs</italic> were characterized as duplicated genes, and displayed a similar exon-intron architecture. All GsMCU proteins contained one conserved MCU domain, within which two transmembrane domains were found. An analysis of the conserved motifs further supported that the GsMCUs showed high conservation in protein sequence and structure. Moreover, we found that all <italic>GsMCUs</italic> were expressed ubiquitously in different tissues and organs, and <italic>GsMCU</italic>s from the same subgroup displayed varied tissue expression profiles. In addition, based on RNA-seq and qRT-PCR assays, six and nine <italic>GsMCUs</italic> were differentially expressed under cold and carbonate alkaline stress, respectively. Promoter analysis also uncovered the existence of two canonical cold-related <italic>cis</italic>-acting elements, LTR and DRE/CRT, as well as stress-related phytohormone-responsive elements. Our results provide valuable information about the MCU family in soybean responses to cold and carbonate alkaline stress, which will be helpful in further characterizing their biological roles in response to abiotic stress.</p>