Plants have high requirements for suitable environmental conditions, and global crop production systems are threatened by a rapidly changing and increasingly unpredictable climate. Scientists warn that climate change will cause extreme weather conditions, making it increasingly difficult to grow enough plants to sustain the world population. The United Nations Environment Program (UNEP) has pointed out that some crops, such as maize and wheat, may produce more potential toxins to protect themselves from extreme weather. Fortunately, over the long course of evolution, plants have evolved multiple complex networks of interconnected signaling pathways that allow them to flexibly acclimate to and overcome stress conditions. In addition to the antioxidant system, plants have also evolved other mechanisms to prevent cellular damage under temperature stress. Thorough study of molecular stress tolerance mechanisms and identification of stress-responsive genes are therefore important for the future of crop production.
Plant hormones are key regulators of many aspects of plant stress resistance. Strigolactones are carotenoid-derived phytohormones that affect plant growth and development in multiple ways. Previous studies have shown that strigolactones can actively regulate the chilling resistance of pea and Arabidopsis thaliana (Arabidopsis) and the cold tolerance of rice; they can also reduce the adverse effects of heat stress on the growth of tall fescue leaves. Strigolactones enhance the drought tolerance of Arabidopsis, Lotus japonicus, and tomato and induce the expression of a heat shock response protein gene (HSP) in Arabidopsis. However, the functions of strigolactones have not previously been investigated in tomato.
Recently, scientists from Zhejiang University found that strigolactones can regulate tomato heat and cold tolerance; their article is published in “Horticulture Research”. Their findings confirm that strigolactones act as positive regulators of tomato heat and cold tolerance and therefore provide an efficient means of cultivating new cold- and heat-tolerant tomato varieties.The researchers constructed transgenic plants through the use of virus-induced gene silencing (VIGS) and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technologies and conducted a detailed study on the important role of strigolactone in tomato heat and cold tolerance. They found that strigolactone-mediated temperature stress tolerance involved the induction of related genes, such as C-repeat binding factor (CBF) and heat shock protein (HSP), as well as antioxidant metabolism and ABA biosynthesis.
“The crosstalk between strigolactones and ABA may play a critical role in the plant response to stresses, but it remains to be studied how ABA biosynthesis is induced by strigolactones and how ABA regulates the transcription of CBF1 and HSP70 under temperature stresses”, Professor Yu said. Certainly, the findings of this team provide us with a deeper understanding of the significant role of strigolactones in stress tolerance mechanisms.
Strigolactones positively regulate abscisic acid-dependent heat and cold tolerance in tomato
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