Nejvíce citovaný článek - PubMed ID 23759105
Spontaneous mutation 7B-1 in tomato impairs blue light-induced stomatal opening
BACKGROUND: The 7B-1 tomato line (Solanum lycopersicum cv. Rutgers) is a photoperiod-sensitive male-sterile mutant, with potential application in hybrid seed production. Small RNAs (sRNAs) in tomato have been mainly characterized in fruit development and ripening, but none have been studied with respect to flower development and regulation of male-sterility. Using sRNA sequencing, we identified miRNAs that are potentially involved in anther development and regulation of male-sterility in 7B-1 mutant. RESULTS: Two sRNA libraries from 7B-1 and wild type (WT) anthers were sequenced and thirty two families of known miRNAs and 23 new miRNAs were identified in both libraries. MiR390, miR166, miR159 were up-regulated and miR530, miR167, miR164, miR396, miR168, miR393, miR8006 and two new miRNAs, miR#W and miR#M were down-regulated in 7B-1 anthers. Ta-siRNAs were not differentially expressed and likely not associated with 7B-1 male-sterility. miRNA targets with potential roles in anther development were validated using 5'-RACE. QPCR analysis showed differential expression of miRNA/target pairs of interest in anthers and stem of 7B-1, suggesting that they may regulate different biological processes in these tissues. Expression level of most miRNA/target pairs showed negative correlation, except for few. In situ hybridization showed predominant expression of miR159, GAMYBL1, PMEI and cystatin in tapetum, tetrads and microspores. CONCLUSION: Overall, we identified miRNAs with potential roles in anther development and regulation of male-sterility in 7B-1. A number of new miRNAs were also identified from tomato for the first time. Our data could be used as a benchmark for future studies of the molecular mechanisms of male-sterility in other crops.
We reported earlier that 7B-1 mutant in tomato (Solanum lycopersicum L., cv. Rutgers), an ABA overproducer, is defective in blue light (B) signaling leading to B-specific resistance to abiotic and biotic stresses. Using a methylation-sensitive amplified polymorphism (MSAP) assay, a number of genes were identified, which were differentially methylated between 7B-1 and its wild type (WT) seedlings in white (W), blue (B), red (R) lights and dark (D) or in response to exogenous ABA and mannitol-induced stresses. The genomic methylation level was almost similar in different lights between 7B-1 and WT seedlings, while significant differences were observed in response to stresses in D, but not B. Using a cDNA-AFLP assay, several transcripts were identified, which were differentially regulated between 7B-1 and WT by B or D or in response to stresses. Blue light receptors cryptochrome 1 and 2 (CRY1 and CRY2) and phototropin 1 and 2 (PHOT1 and PHOT2) were not affected by the 7B-1 mutation at the transcriptional level, instead the mutation had likely affected downstream components of the light signaling pathway. 5-azacytidine (5-azaC) induced DNA hypomethylation, inhibited stem elongation and differentially regulated the expression of a number of genes in 7B-1. In addition, it was shown that mir167 and mir390 were tightly linked to auxin signaling pathway in 5-azaC-treated 7B-1 seedlings via the regulation of auxin-response factor (ARF) transcripts. Our data showed that DNA methylation remodeling is an active epigenetic response to different lights and stresses in 7B-1 and WT, and highlighted the differences in epigenetic and transcriptional regulation of light and stress responses between 7B-1 and WT. Furthermore, it shed lights on the crosstalk between DNA hypomethylation and miRNA regulation of ARFs expression. This information could also be used as a benchmark for future studies of male-sterility in other crops.
- MeSH
- genetická transkripce * genetika účinky záření MeSH
- metylace DNA * genetika účinky záření MeSH
- mutace MeSH
- neplodnost rostlin * MeSH
- rostlinné proteiny * biosyntéza genetika MeSH
- Solanum lycopersicum * genetika metabolismus MeSH
- světlo * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- rostlinné proteiny * MeSH
