Comparative transcriptome analysis reveals phytohormone signalings, heat shock module and ROS scavenger mediate the cold-tolerance of rubber tree

Abstract

Two contrasting cold response rubber tree clones, the cold-resistant ‘93-114’ and cold-sensitive ‘Reken501’, were subject to a global transcriptome response assessing via high-throughput RNA-seq technique and comprehensive bioinformatics analysis using the referenced rubber tree genome with the purpose of exploring the potential molecular cues underlying the tolerance of rubber trees to cold stress. As a result, a total of 1919 genes had significantly higher expression, while 2929 genes had significantly lower expression in ‘93–114’ than in ‘Reken501’ without cold stress. Upon cold stress, the numbers of genes with significantly higher expression decreased to 1501 at 1 h treatment and to 1285 at 24 h treatment in ‘93–114’ than that of ‘Reken501’, conversely, the numbers of genes with significantly lower expression increased to 7567 at 1 h treatment and to 5482 at 24 h treatment. Functional annotation of the differentially expressed genes between ‘93–114’ and ‘Reken501’ suggests that down-regulation of auxin and ethylene signaling and activation of heat shock module and ROS scavengers is a primary strategy for H. brasiliensis to cope with cold stress. Our identified vital differentially expressed genes may be beneficial for elucidation of the molecular mechanisms underlying cold tolerance and for genetic improvement of H. brasiliensis clones.

Two HbHsfA1 and HbHsfB1 genes from the tropical woody plant rubber tree confer cold stress tolerance in Saccharomyces cerevisiae

“…Two important criteria, |log2Fold change C 1| and FDR B 0.001, were used to assess significant differences in gene expression in the two rubber clones. Two differentially expressed Hsf genes (scaffold0026_252701 and scaf-fold0040_3084829) were selected for further investigation of their functions in cold stress responses among the differentially expressed gene data set as described previously (Deng et al 2018). Primers were designed to isolate the full-length coding region and the 3 0 region sequences of the two Hsf genes after comparison with the public refined rubber tree genome data (Tang et al 2016); these primers include the following:…”

“…The cold-tolerant rubber tree clone '93-114' and cold-sensitive clone 'Reken501' were subjected to transcriptome-level sequence (https://www.ncbi.nlm.nih. gov/geo/query/acc.cgi?acc=GSE67559) and analysed to identify the candidate cold-stress-response genes (Deng et al 2018). Two Hsf-type genes, designated as HbHsfA1 and HbHsfB1 based on their homology comparison of amino acid sequences, were identified as differentially expressed genes between the cold-resistant rubber clone '93-114' and the cold-sensitive rubber tree clone 'Reken501' under cold stress treatment, and their functions in cold stress regulation were analysed in this study.…”

Defence‐related priming and responses to recurring drought: Two manifestations of plant transcriptional memory mediated by the ABA and JA signalling pathways

“…This conclusion is supported by the fact that diverse phytohormones mediate stress signalling pathways and TFs coregulate (both synergistically and antagonistically) overlapping gene sets (Ahmad et al, ; Bostock, Pye, & Roubtsova, ; Huang et al, ; Prasch & Sonnewald, ; Rieman et al, ). Moreover, hormone‐activated signalling pathways raise the levels of other signalling molecules (reactive oxygen species (ROS) and phosphoinositides) that function as secondary messengers for the networks that close stomata and affect cellular homeostasis and gene expression (Balla, ; Choi, Lee, Jeon, Staiger, & Lee, ; Deng et al, ; Ding et al, ; Ding, Ndamukong, Zhao, et al, ; Locato et al, ; Murata, Mori, & Munemasa, ; Nagpal, Hassan, Ndamukong, Avramova, & Baluška, ; Ndamukong, Jones, Lapko, Divecha, & Avramova, ; Turkan, ; Wang & Song, ). The measured transcript levels for any stress responding gene, therefore, represent the compound effect from the activity of complex signalling networks.…”

Genome-Wide Identification and Characterization of Heat-Shock Transcription Factors in Rubber Tree

“…Moreover, some of the FvHsf proteins of Fragaria vesca were reported to localize to both the nucleus and cytosol, such as FvHsfA2a, FvHsfA3a, FvHsfA4a, FvHsfA5a, FvHsfB2b, and FvHsfC1a [12]. While HbHsfA2b was only detected in the nucleus (Figure 6A), the expression of a number of sHSPs was significantly activated upon cold stress in cold-tolerant rubber-tree clone 93-114 in comparison with cold-sensitive rubber-tree clone Reken501 [16]. These data suggest that HbHsfA2b may be involved in activating some sHSPs in the rubber tree in a similar manner to HsfA2 in Arabidopsis.…”

“…Hsfs may be involved in enhanced cold tolerance. However, information regarding Hsfs is limited [16,17] despite four versions of the rubber-tree genome having been published [18][19][20][21].…”