Heat Shock Factor Genes of Tall Fescue and Perennial Ryegrass in Response to Temperature Stress by RNA-Seq Analysis

Abstract

Heat shock factors (Hsfs) are important regulators of stress-response in plants. However, our understanding of Hsf genes and their responses to temperature stresses in two Pooideae cool-season grasses, Festuca arundinacea, and Lolium perenne, is limited. Here we conducted comparative transcriptome analyses of plant leaves exposed to heat or cold stress for 10 h. Approximately, 30% and 25% of the genes expressed in the two species showed significant changes under heat and cold stress, respectively, including subsets of Hsfs and their target genes. We uncovered 74 Hsfs in F. arundinacea and 52 Hsfs in L. perenne, and categorized these genes into three subfamilies, HsfA, HsfB, and HsfC based on protein sequence homology to known Hsf members in model organisms. The Hsfs showed a strong response to heat and/or cold stress. The expression of HsfAs was elevated under heat stress, especially in class HsfA2, which exhibited the most dramatic responses. HsfBs were upregulated by the both temperature conditions, and HsfCs mainly showed an increase in expression under cold stress. The target genes of Hsfs, such as heat shock protein (HSP), ascorbate peroxidase (APX), inositol-3-phosphate synthase (IPS), and galactinol synthase (GOLS1), showed strong and unique responses to different stressors. We comprehensively detected Hsfs and their target genes in F. arundinacea and L. perenne, providing a foundation for future gene function studies and genetic engineering to improve stress tolerance in grasses and other crops.

Flexible shift on gene body methylation and transcription of LpCYP72A161 exposed to temperature stress in perennial ryegrass

“…Thus, the gene was named LpCYP72A161, a gene belonging to the subfamily CYP72A. Taking together results from our present and previous studies (Wang et al, 2015b), LpCYP72A161 showed a significant up-regulation upon both heat and cold stresses, suggesting that it may play a potential role in temperature stress response. While genetic sequences of CYP72A161 have been identified, the gene's function has not been studied.…”

“…In our previously published work (Wang et al, 2015b), we noted a high number of differentially expressed P450 s under heat and cold stress, suggesting that P450 s play an important role in the perennial ryegrass's adaption to temperature stress. Of the P450 genes, six were divided to CYP72A subfamily according to the amino acid sequence homology (Table S2).…”

“…Previously, it was shown that LpCYP72A161 expression increases significantly when plants were subjected to temperature stress by RNAseq (Table S2) (Wang et al, 2015b). Here, the LpCYP72A161 expression levels at different treatments (CK, HS, HR, and CS) were further analyzed by qRT-PCR.…”

“…Furthermore, we also characterized genes that respond to heat or cold stress in perennial ryegrass (Wang et al, 2015b), and found that high number of P450 s (cytochrome P450, CYP) showed significant change in gene expression under heat and cold stress. We cloned a P450 gene (LpCYP72A161) that showed remarkable up-regulation under heat and cold treatment.…”

Differential Acclimation of Enzymatic Antioxidant Metabolism and Photosystem II Photochemistry in Tall Fescue under Drought and Heat and the Combined Stresses

“…Of course, the gene expression of psbA, psbB , and psbC is not enough. Wang et al ( 2015 ) have researched that Hsfs and their target genes in F. arundinacea and L. perenne also provied a foundation for future gene function studies to improve stress tolerance in grasses and other crops. Yang et al ( 2015 ) also have reported that TIP41 combined with TUB and ACT was stably expressed in heat-stressed leaves and these suitable reference genes in tall fescue would allow for more accurate identification of stress-tolerance genes in this stress-tolerant species.…”