Singh Achuit K, Mishra Pallavi, Kashyap Sarvesh Pratap, Karkute Suhas G, Singh Prabhakar Mohan, Rai Nagendra, Bahadur Anant, Behera Tusar K
Division of Crop Improvement, ICAR-Indian Institute of Vegetable Research, Varanasi, Uttar Pradesh, India.
Division of Crop Production, ICAR-Indian Institute of Vegetable Research, Varanasi, Uttar Pradesh, India.
Front Plant Sci. 2022 Oct 25;13:1040532. doi: 10.3389/fpls.2022.1040532. eCollection 2022.
Plant productivity is being seriously compromised by climate-change-induced temperature extremities. Agriculture and food safety are threatened due to global warming, and in many cases the negative impacts have already begun. Heat stress leads to significant losses in yield due to changes in growth pattern, plant phonologies, sensitivity to pests, flowering, grain filling, maturity period shrinkage, and senescence. Tomato is the second most important vegetable crop. It is very sensitive to heat stress and thus, yield losses in tomato due to heat stress could affect food and nutritional security. Tomato plants respond to heat stress with a variety of cellular, physiological, and molecular responses, beginning with the early heat sensing, followed by signal transduction, antioxidant defense, osmolyte synthesis and regulated gene expression. Recent findings suggest that specific plant organs are extremely sensitive to heat compared to the entire plant, redirecting the research more towards generative tissues. This is because, during sexual reproduction, developing pollens are the most sensitive to heat. Often, just a few degrees of temperature elevation during pollen development can have a negative effect on crop production. Furthermore, recent research has discovered certain genetic and epigenetic mechanisms playing key role in thermo-tolerance and have defined new directions for tomato heat stress response (HSR). Present challenges are to increase the understanding of molecular mechanisms underlying HS, and to identify superior genotypes with more tolerance to extreme temperatures. Several metabolites, genes, heat shock factors (HSFs) and microRNAs work together to regulate the plant HSR. The present review provides an insight into molecular mechanisms of heat tolerance and current knowledge of genetic and epigenetic control of heat-tolerance in tomato for sustainable agriculture in the future. The information will significantly contribute to improve breeding programs for development of heat tolerant cultivars.
气候变化导致的极端温度正在严重损害植物生产力。由于全球变暖，农业和食品安全受到威胁，而且在许多情况下，负面影响已经开始显现。热应激会导致生长模式、植物物候、对害虫的敏感性、开花、灌浆、成熟期缩短和衰老等方面发生变化，从而造成产量大幅损失。番茄是第二重要的蔬菜作物。它对热应激非常敏感，因此，热应激导致的番茄产量损失可能会影响粮食和营养安全。番茄植株对热应激会产生多种细胞、生理和分子反应，从早期的热感知开始，接着是信号转导、抗氧化防御、渗透调节物质合成和基因表达调控。最近的研究结果表明，与整个植株相比，特定的植物器官对热极其敏感，这使得研究更多地转向生殖组织。这是因为在有性生殖过程中，发育中的花粉对热最为敏感。通常，在花粉发育期间，仅仅几度的温度升高就可能对作物产量产生负面影响。此外，最近的研究发现某些遗传和表观遗传机制在耐热性中起关键作用，并为番茄热应激反应（HSR）确定了新的方向。目前的挑战是加深对热应激潜在分子机制的理解，并识别出对极端温度更具耐受性的优良基因型。几种代谢物、基因、热休克因子（HSF）和微小RNA共同作用来调节植物的热应激反应。本综述深入探讨了耐热性的分子机制以及番茄耐热性遗传和表观遗传控制的当前知识，以促进未来的可持续农业发展。这些信息将极大地有助于改进培育耐热品种的育种计划。
