[Cloning of GmHSFA1 gene and its overexpression leading to enhancement of heat tolerance in transgenic soybean].
Heat shock transcription factors (HSFs) are important in regulating heat stress response by mediating expression of heat shock protein (HSP) genes in various plant species. In the present study, a novel GmHSFA1 with an ORF of 1,533 bp (full-length cDNA sequence of 1,781 bp) was cloned from soybean genome via comparative genomic approach and RACE (rapid amplification of cDNA ends). This gene encodes 510 amino acids consisting of a protein of 56.2 kDa (GenBank accession number: AY458843). Similar to other HSFs, GmHSFA1 has the basic modular structure including DBD, OD, NLS, and CTAD. BLAST analysis revealed the identity of 52.46% between amino acid sequences between GmHSFA1 and LpHSFA1 that has the highest similarity to GmHSFA1 in all HSFA1s in various plant species. The results from RT-PCR, Northern blotting, and transformation showed: 1) GmHsfA1 exhibited the constitutive expression patterns in different tissues of soybean; 2) The expression level of GmHsfA1 in transgenic plants was notably higher than that in non-transgenic plants; 3) Overexpression of GmHsfA1 activated transcription of GmHSP22 in transgenic plants under normal conditions and enhanced obviously expressions of GmHSP23 and GmHSP70 in transgenic plants under heat stress conditions; 4) Heat tolerant temperature (as high as 52 degrees C) of transgenic plants was remarkably higher than that of non-transgenic plants. These results preliminarily proved that the overexpression of GmHsfA1 possibly led to the notable enhancement of heat-tolerant level of transgenic plants by mediating the activation of transcription or improvement of expression of some GmHSPs in the GmHsfA1's downstream in transgenic plants, suggesting GmHSFA1 is a novel and functional heat shock transcription factor of soybean.
Chen
Xiao-Jun
XJ
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Ye
Chun-Jiang
CJ
Lü
Hui-Ying
HY
Xu
Min-Xin
MX
Li
Wei
W
Zhang
Li-Ming
LM
Wang
Chao
C
Luo
Shu-Ping
SP
Zhu
Bao-Ge
BG
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D015870:Gene Expression; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006358:Hot Temperature; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D030821:Plants, Genetically Modified; D016415:Sequence Alignment; D013025:Glycine max / Q000166:cytology / Q000235:genetics* / Q000502:physiology*; D013312:Stress, Physiological / Q000235:genetics; D013997:Time Factors; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D010940:Plant Proteins; D014157:Transcription Factors