BrrICE1.1 is associated with putrescine synthesis through regulation of the arginine decarboxylase gene in freezing tolerance of turnip (Brassica rapa var. rapa)

Abstract

Background In the agricultural areas of Qinghai-Tibet Plateau, temperature varies widely from day to night during the growing season, which makes the extreme temperature become one of the limiting factors of crop yield. Turnip (Brassica rapa var. rapa) is a traditional crop of Tibet grown in the Tibet Plateau, but its molecular and metabolic mechanisms of freezing tolerance are unclear. Results Here, based on the changes in transcriptional and metabolic levels of Tibetan turnip under freezing treatment, the expression of the arginine decarboxylase gene BrrADC2.2 exhibited an accumulative pattern in accordance with putrescine content. Moreover, we demonstrated that BrrICE1.1 (Inducer of CBF Expression 1) could directly bind to the BrrADC2.2 promoter, activating BrrADC2.2 to promote the accumulation of putrescine, which was verified by RNAi and overexpression analyses for both BrrADC2.2 and BrrICE1.1 using transgenic hair root. The function of putrescine in turnip was further analyzed by exogenous application putrescine and its inhibitor DL-α-(Difluoromethyl) arginine (DFMA) under freezing tolerance. In addition, the BrrICE1.1 was found to be involved in the ICE1-CBF pathway to increase the freezing stress of turnip. Conclusions BrrICE1.1 could bind the promoter of BrrADC2.2 or CBFs to participate in freezing tolerance of turnip by transcriptomics and targeted metabolomics analyses. This study revealed the regulatory network of the freezing tolerance process in turnip and increased our understanding of the plateau crops response to extreme environments in Tibet.

Grafting Watermelon Onto Pumpkin Increases Chilling Tolerance by Up Regulating Arginine Decarboxylase to Increase Putrescine Biosynthesis

“…In the current study, our data demonstrated that pumpkin rootstock grafting played a positive role in putrescine synthesis and accumulation under chilling stress (Figure 2A), consistent with the up-regulated expression of the ADC gene (Figures 4, 7). Similarly, an increase in expression of the ADC gene and accumulation of putrescine under chilling stress have been reported in Brassica rapa (Yin et al, 2020). Moreover, a foliar spray D-arginine experiment further confirmed that putrescine under chilling stress in Cl/Cm inhibits ADC activity to modulate the metabolism of plants and the production of metabolites involved in stress tolerance (Song et al, 2014a(Song et al, , 2021Wu et al, 2016;Wang et al, 2019).…”

Response of distribution patterns of two closely related species in Taxus genus to climate change since last inter‐glacial

“…Second, from the view of biological characteristics, Taxus prefers a shady and humid environment (Wu & Wen, 2017 ). However, with the rising temperature, the climatic conditions such as strong radiation, drought, wind, and other adverse climatic conditions will be more severe in high‐altitude areas (Ouyang et al, 2022 ; Solomon et al, 2007 ; Yin et al, 2020 ). Thus, these adverse conditions will pose relatively more physiological constraints on T. chinensis , thus resulting in range reduction.…”

Putrescine: A Key Metabolite Involved in Plant Development, Tolerance and Resistance Responses to Stress

“…A positive correlation was observed between agmatine content and primary root growth rate, whereas no correlation was found with Put, or they were even negatively correlated. In this regard, the expression of BrrADC2.2 followed a cumulative pattern in accordance with Put levels in Tibetan turnip ( Brassica rapa ) under freezing conditions [ 162 ]. It was found that BrrICE1.1 (Inducer of CBF Expression 1) could directly interact with the BrrADC2.2 promoter, activating BrrADC2.2 to stimulate the accumulation of Put levels.…”