The Alfin-like transcription factors: Identification, characterization, and expression analysis in Pyrus bretschenedri provide insight into its divergent functions on abiotic response

In the previous decades, numerous investigations have been done that the Alfin-like (AL) transcription factors (TFs) are participating in several physiological and development processes in plants including root hair elongation, development of root and meristem, etc. Although the AL-TFs had been comprehensively evaluated in several species, the little finding is reported on the AL-TFs in Chinese pear (Pyrus bretschenedri). In the current study, 15 PbAL genes were systemically characterized and nomenclature as PbAL1 to PbAL15 corresponding to their chromosomal localization. Phylogeny analysis and structural features revealed that the 15 genes could be classified into six subfamilies (S-I to S-VI).Whole-genome duplication (WGD) events are the most common mechanism and may play a crucial role in the expansion of the AL gene family. Microsynteny analysis among Pyrus bretschenedri, Fragaria vesca, Prunus avium, Prunus mume, and Prunus persica showed that AL duplicated regions were more conserved and undergo purifying selection during the evolutionary process. Further analysis of introns-exons, physicochemical properties, and conserved motif showed their functional divergence, diversification in quantity, and structure. The expression pattern of PbAL gene family in various organs and different fruit development stages were conducted through transcriptomic data. Moreover, stress-related cis-acting elements of PbAL genes were found on the promoters regions to be associated with hormonal and environmental stress responses. Noticeably, the expression patterns evaluated by qRT-PCR demonstrated that PbAL genes were differentially expressed under indole acetic acid (IAA), Gibberellic acid (GA), Melatonin (ME) and abscisic acid (ABA) treatment, which response to abiotic stress and fruit growth development. Current work explored the potential function and evolution of PbAL genes in Pyrus bretschenedri. PbAL were investigated as candidate genes for further research and important clues for improving fruit quality through molecular breeding.