Genome-wide identification and characterization of the lettuce GASA family in response to abiotic stresses

Abstract

AbstractBackgroundLettuce is one of the most extensively farmed vegetables in the world, and it prefers cool growing conditions. High temperatures promote premature bolt formation, reducing quality and yield. The gibberellic acid-stimulatedArabidopsis(GASA) family genes play critical roles in plant growth, development, and stress responses. However, the biological functions of GASA proteins in lettuce have yet to be thoroughly investigated.ResultsUsing genome-wide analysis, 20GASAs were identified in lettuce including, three groups of LsGASA proteins based on the phylogenetic analysis. Except for one, all GASA proteins included a conserved GASA domain with 12 cysteine residues.Cis-element analysis showed thatLsGASAs were closely associated with light, phytohormones, and stress resistance. Five segmental and three tandem duplication events were observed in theLsGASAfamily based on duplication analysis.GASAsynteny analysis among lettuce,Arabidopsis,tobacco, and rice revealed thatLsGASA5is highly collinear with all species. Six of the 20LsGASAshowed increased expression patterns at specific time points in the shoot apical meristem when subjected to heat stress. According to gene expression analysis, the majority ofGASAwere highly expressed in flowers compared to other organs, and sixGASAexhibited highly increased expression levels in response to NaCl, abscisic acid, and gibberellin treatment. Furthermore, LsGASA proteins are predominantly found in the plasma membrane and/or the cytosol.ConclusionsThis study provides a comprehensive characterization ofLsGASAgenes for their diversity and biological functions. Moreover, our results will be useful for further studies on the function of lettuceGASAin abiotic stress- and heat-induced bolting signaling.