Identification and genetic analysis of alternative splicing of long non-coding RNAs in tomato initial flowering stage.

Alternative splicing (AS) is a key modulator of development in many eukaryotic organisms. Long non-coding RNAs (lncRNAs) are a class of non-coding RNAs that play essential regulatory roles in various developmental processes and stress responses. However, the functions of AS lncRNAs during the initial flowering of tomato are largely unknown. This study was designed to investigate the AS pattern of lncRNAs in tomato flower, leaf, and root tissues at the initial flowering stage. Using RNA-Seq, we found that 72.55% of lncRNAs underwent AS in these tissues, yielding a total of 16,995 AS events. Among them, the main type of AS event is alternative first exon (AFE), followed by retained intron (RI). We performed candidate target genes analysis on tissue-specific AS lncRNA, and the results indicated that the candidate target genes of these lncRNAs may be involved in the regulation of circadian rhythm, plant immunity, cellulose synthesis and phosphate-containing compound metabolic process. Moreover, a total of 73,085 putative SNPs and 15,679 InDels were detected, and the potential relationship between the AS of lncRNAs and interesting SNP and InDel loci, as well as their numbers, revealed their effects on tomato genetic diversity and genomic stability. Our data provide new insights into the complexity of the transcriptome and the regulation of AS.