Resumo Vários estresses abióticos afetam o crescimento e desenvolvimento de plantas, sendo um deles responsável por severas perdas na produção de culturas e hortícolas no mundo, o estresse por calor. Nesse artigo, o efeito do estresse por calor (superior a 30-35 °C para diferentes espécies) em culturas e plantas hortícolas e seu efeito na indução de outros estresses, incluindo estresse osmótico e oxidativo são discutidos. As plantas demonstram respostas bioquímicas e moleculares após receberem sinais ambientais como altas temperaturas e toleram condições indesejáveis.

Abstract Various abiotic stresses affect growth and development of plants and one of them that causes severely decreasing the horticultural and crop yields is the heat stress worldwide. In this paper, the effects of heat (more than 30-35 °C in different species) stress on the horticultural plants and crops, and its effects on inducing other stresses, including osmotic and oxidative stresses are discussed. Plants show the molecular and biochemical responses after receiving environmental signals such as high temperatures and tolerate undesirable conditions.

Abstract Various abiotic stresses affect growth and development of plants and two important cues that cause to sever decrease the horticultural and crops yield are the heat and chilling stresses worldwide. Plants have various mechanisms to tolerate or avoid the stresses; one of these mechanisms is the biosynthesis of organic solutes. In this paper, effects of chilling (0-15 °C) stress on the horticultural (ornamental and vegetable) plants and crops are discussed. You will see that plants how to tolerate the stress by organic solutes. The most important organic molecules to regulate water relations in plants are introduced. The organic solutes that also are called osmo-protectants include soluble carbohydrates, amino acids and nitrogen compounds.