AUTHOR=Zhang Yujing , Fan Nana , Wen Wuwu , Liu Siyan , Mo Xin , An Yuan , Zhou Peng 

TITLE=Genome−wide identification and analysis of LEA_2 gene family in alfalfa (Medicago sativa L.) under aluminum stress

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.976160

DOI=10.3389/fpls.2022.976160

ISSN=1664-462X

ABSTRACT=<p>Late embryonic development abundant proteins (LEAs) are a large family of proteins commonly existing in plants. LEA_2 is the largest subfamily in the LEA, it plays an important role in plant resistance to abiotic stress. In order to explore the characteristics of <italic>LEA_2</italic> gene family members in alfalfa (<italic>Medicago sativa</italic> L.), 155 members of <italic>LEA_2</italic> (<italic>MsLEA_2</italic>) family were identified from alfalfa genome. Bioinformatics analysis was conducted from the aspects of phylogenetic relationship, chromosome distribution, chromosome colinearity, physical and chemical properties, motif composition, exon-intron structure, <italic>cis</italic>-element and so on. Expression profiles of <italic>MsLEA_2</italic> gene were obtained based on Real-time fluorescent quantitative PCR (qRT-PCR) analysis and previous RNA-seq data under aluminum (Al) stress. Bioinformatics results were shown that the <italic>MsLEA_2</italic> genes are distributed on all 32 chromosomes. Among them, 85 genes were present in the gene clusters, accounting for 54.83%, and chromosome Chr7.3 carries the largest number of <italic>MsLEA_2</italic> (19 <italic>LEA_2</italic> genes on Chr7.3). Chr7.3 has a unique structure of <italic>MsLEA_2</italic> distribution, which reveals a possible special role of Chr7.3 in ensuring the function of <italic>MsLEA_2</italic>. Transcriptional structure analysis revealed that the number of exons in each gene varies from 1 to 3, and introns varies from 0 to 2. <italic>Cis</italic>-element analysis identified that the promoter region of <italic>MsLEA_2</italic> is rich in ABRE, MBS, LTR, and MeJARE, indicating <italic>MsLEA_2</italic> has stress resistance potential under abiotic stress. RNA-seq data and qRT-PCR analyses showed that most of the <italic>MsLEA_2</italic> members were up-regulated when alfalfa exposed to Al stress. This study revealed that phylogenetic relationship and possible function of <italic>LEA_ 2</italic> gene in alfalfa, which were helpful for the functional analysis of LEA_ 2 proteins in the future and provided a new theoretical basis for improving Al tolerance of alfalfa.</p>