Functional characterization of maize heat shock transcription factor gene in thermotolerance.

BACKGROUND

Heat waves can critically influence maize crop yields. Plant heat shock transcription factors (HSFs) play a key regulating role in the heat shock (HS) signal transduction pathway.

METHOD

In this study, a homologous cloning method was used to clone HSF gene (accession number: MK888854) from young maize leaves. The transcript levels of were detected using qRT-PCR in different tissues and treated by HS, abscisic acid (ABA), hydrogen peroxide (HO), respectively, and the functions of gene were studied in transgenic yeast and .

RESULT

had a coding sequence (CDS) of 1176 bp and encoded a protein consisting of 391 amino acids. The homologous analysis results showed that ZmHsf01 and SbHsfA2d had the highest protein sequence identities. Subcellular localization experiments confirmed that ZmHsf01 was localized in the nucleus. was expressed in many maize tissues. It was up-regulated by HS, and up-regulated in roots and down-regulated in leaves under ABA and HOtreatments. -overexpressing yeast cells showed increased thermotolerance. In seedlings, compensated for the thermotolerance defects of mutant , and -overexpressing lines showed enhanced basal and acquired thermotolerance. When compared to wild type (WT) seedlings, -overexpressing lines showed higher chlorophyll content and survival rates after HS. Heat shock protein (HSP) gene expression levels were more up-regulated in -overexpressing seedlings than WT seedlings. These results suggest that plays a vital role in response to HS in plant.