Temperature Stress in Plants

Abstract

Abstract Temperature stress in plants is classified into three types depending on the stressor, which may be high, chilling or freezing temperature. Temperature‐stressed plants show low germination rates, growth retardation, reduced photosynthesis, and often die. The elucidation of mechanisms by which temperature stress causes disorders is important to reveal responses by which plants cope with adverse temperature conditions. However, plants respond to temperature stress by regulating membrane lipid composition, stress‐related transcription factors, metabolite synthesis and detoxification pathways. Such plant molecular responses to temperature stress will help establish genetic engineering techniques to produce temperature stress‐tolerant plants. Genetic engineering techniques have been applied to improve the adaptability of plants by altering temperature stress‐related gene expression in response to unfavourable temperature conditions. In this article, the authors focus on plant responses and adaptation to temperature stress and strategies for the genetic improvement of temperature stress tolerance in plants. Key Concepts: Plants cope with adverse temperature stress by altering molecular mechanisms involving proteins, antioxidants, metabolites, regulatory factors, other protectants and membrane lipids. Thermotolerance is closely correlated with the production of toxic acrolein and methyl vinyl ketone from membrane trienoic fatty acids under heat stress, and it is possible to produce thermotolerant plants with reduced trienoic fatty acid contents. Regulatory factors such as heat shock factors directly and/or indirectly induce accumulation of stress‐related gene products under high temperature conditions and contribute to thermotolerance. Under high temperature conditions, several protectants, such as glycinebetaine which apparently stabilises photosystem II proteins, accumulate to protect proteins and photosystems in plants. Antioxidants decrease levels of stress‐inducible reactive oxygen species, contributing to improved tolerance to cold as well as high temperature stress.