AbstractAn Arabidopsis mutant named defective repression of OLE3::LUC 1 (drol1) was originally isolated as a mutant with defects in the repression of OLEOSIN3 (OLE3) after seed germination. In this study, we show that DROL1 is an Arabidopsis homolog of yeast DIB1, a subunit of U5 snRNP in the spliceosome, but comprises a subfamily specific to a certain class of eukaryotes. Comprehensive analysis of intron splicing by RNA-Seq analysis of drol1 mutants revealed reduced splicing of most of the minor introns with AT–AC dinucleotide termini. Thirty-nine genes, including those playing important roles in the response to abiotic stress, exhibited reduced splicing of AT–AC-type introns in drol1 mutants. In addition, drol1 mutant seedlings showed growth arrest, similar to that caused by the activation of abscisic acid signaling, as a result of reduced splicing of AT–AC-type introns in some genes. These results indicate that DROL1 is specifically involved in the splicing of introns with AT–AC termini, and splicing of these minor introns plays an important role in plant growth and development.
Abscisic Acid Signaling and Abiotic Stress Tolerance in Plants: A Review on Current Knowledge and Future Prospects
