AUTHOR=Jin Jian Feng , He Qi Yu , Li Peng Fei , Lou He Qiang , Chen Wei Wei , Yang Jian Li 

TITLE=Genome-Wide Identification and Gene Expression Analysis of Acyl-Activating Enzymes Superfamily in Tomato (Solanum lycopersicum) Under Aluminum Stress

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.754147

DOI=10.3389/fpls.2021.754147

ISSN=1664-462X

ABSTRACT=<p>In response to changing environments, plants regulate gene expression and subsequent metabolism to acclimate and survive. A superfamily of acyl-activating enzymes (AAEs) has been observed in every class of creatures on planet. Some of plant <italic>AAE</italic> genes have been identified and functionally characterized to be involved in growth, development, biotic, and abiotic stresses <italic>via</italic> mediating diverse metabolic pathways. However, less information is available about AAEs superfamily in tomato (<italic>Solanum lycopersicum</italic>), the highest value fruit and vegetable crop globally. In this study, we aimed to identify tomato AAEs superfamily and investigate potential functions with respect to aluminum (Al) stress that represents one of the major factors limiting crop productivity on acid soils worldwide. Fifty-three <italic>AAE</italic> genes of tomato were identified and named on the basis of phylogenetic relationships between <italic>Arabidopsis</italic> and tomato. The phylogenetic analysis showed that AAEs could be classified into six clades; however, clade III contains no <italic>AAE</italic> genes of tomato. Synteny analyses revealed tomato vegetable paralogs and <italic>Arabidopsis</italic> orthologs. The RNA-seq and quantitative reverse-transcriptase PCR (qRT-PCR) analysis indicated that 9 out of 53 <italic>AAEs</italic> genes were significantly up- or downregulated by Al stress. Numerous <italic>cis</italic>-acting elements implicated in biotic and abiotic stresses were detected in the promoter regions of <italic>SlAAEs</italic>. As the most abundantly expressed gene in root apex and highly induced by Al, there are many potential STOP1 <italic>cis</italic>-acting elements present in the promoter of <italic>SlAAE3-1</italic>, and its expression in root apex was specific to Al. Finally, transgenic tobacco lines overexpressing <italic>SlAAE3-1</italic> displayed increased tolerance to Al. Altogether, our results pave the way for further studies on the functional characterization of <italic>SlAAE</italic> genes in tomato with a wish of improvement in tomato crop in the future.</p>