Maturation of the nodule-specific transcript MsHSF1c in Medicago sativa may involve interallelic trans-splicing.
In nonplant species, many heat-shock transcription factors (HSFs) undergo spatiotemporal-specific alternative splicing. However, little is known about the spatiotemporal-specific splicing of HSFs in plants. Previously, we reported that the alfalfa HSF gene MsHSF1 undergoes multiple alternative splicing events in various tissues. Here, we identified another spliced transcript isoform, MsHSF1c, containing a 177-base tandem repeat, and showed that the low-abundance MsHSF1c is a nodule-specific transcript of MsHSF1. We also found that MsHSF1 presents multiple alleles with single-base variations and the expression of MsHSF1 alleles has allele-specific differences in alfalfa nodules. Because single-base variations at position 1006 change the AT of MsHSF1b to GT in MsHSF1b-3, creating a pair of donor/acceptor sites with the AG of MsHSF1b/1b-1 at position 827-828 for pre-mRNA splicing, we suggest that MsHSF1c may be generated by trans-splicing between alleles MsHSF1b-3 and MsHSF1b or MsHSF1b-1. These results provide new insight into the role of tissue-specific contribution in the transcription of plant HSF genes.
He
Zhi-shui
ZS
National Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Zou
Hua-song
HS
Wang
Yan-zhang
YZ
Zhu
Jia-bi
JB
Yu
Guan-qiao
GQ
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D014644:Genetic Variation; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000235:genetics*; D000455:Medicago sativa / Q000235:genetics*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics; D017422:Sequence Analysis, DNA; D020080:Tandem Repeat Sequences; D020040:Trans-Splicing; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D010940:Plant Proteins; D020033:Protein Isoforms; D014157:Transcription Factors