Low temperature promotes intron retention in two e-cor genes of durum wheat.
Following the screening of a suppression subtractive library developed from durum wheat plants exposed to low temperature for 6 h, two early cold-regulated (e-cor) genes have been isolated. These genes, coding putatively for a ribokinase (7H8) and a C3H2C3 RING-finger protein (6G2), were characterized by the stress-induced retention of a subset of introns in the mature mRNA. This feature was dependent on cold for 7H8 and on cold and dehydration for 6G2. When other genes, such as the stress-related gene WCOR410c, coding for a dehydrin (one intron), or a gene coding for a putative ATP binding cassette transporter (16 introns) were analyzed, no cold-dependent intron retention was observed. Cold-induced intron retention was not observed in mutants defective in the chloroplast development; nevertheless treatment with cycloheximide in the absence of cold was able to promote intron retention for the 7H8 e-cor gene. These results suggest that the cold-induced intron retention reflects the response of the spliceosoma to specific environmental signals transduced to the splicing protein factors through a chloroplast-dependent pathway. Notably, when the 7H8 Arabidopsis orthologous gene was analyzed, no stress induction in terms of mRNA abundance and no cold-dependent intron retention was detected. Otherwise, 6G2 Arabidopsis homologous sequences sharing the same genomic structure of the durum wheat 6G2 showed a similar intron retention event although not strictly dependent on stress.
Mastrangelo
Anna Maria
AM
Experimental Institute for Cereal Research, S.S. 16 km 675, 71100 Foggia, Italy. mastrangelo@iscfoggia.it
Belloni
Sara
S
Barilli
Samantha
S
Ruperti
Benedetto
B
Di Fonzo
Natale
N
Stanca
Antonio Michele
AM
Cattivelli
Luigi
L
D017360:Arabidopsis / Q000378:metabolism; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D003080:Cold Temperature; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D001467:Hordeum / Q000235:genetics / Q000378:metabolism; D007438:Introns / Q000502:physiology*; D009154:Mutation; D010940:Plant Proteins / Q000378:metabolism; D014908:Triticum / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
D010940:Plant Proteins