Journal of Scientifc Agriculture 2020, 4: 38-44 doi: 10.25081/jsa.2020.v4.6110 http://updatepublishing.com/journal/index.php/jsa 38 J Sci Agric • 2020 • Vol 4 INTRODUCTION Environmental stress such as cold, heat, salinity and drought adversely affect growth and productivity and trigger a series of morphological, physiological, biochemical and molecular changes in plants that eventually interrupt plant life [1]. Stress can be defined as any substance or condition which stops a plant’s metabolism, development or growth [2]. Any element that decreases plant reproduction and development below the genotype’s potential considered as stress [3]. Cold stress (chilling and freezing) affect crop productivity because many crops are sensitive and intolerant to low temperature. Acute temperature variation damages the plants [4]. Usually, chilling and freezing stress lead to chlorosis, necrosis, membrane damage, changes in cytoplasm viscosity, and changes in enzyme activities [5] leading to death of plants. Vegetables are sensitive crops and their production is hindered by various abiotic stresses. During winter season, low temperature stress adversely damages vegetable production. Low temperature stress has been reported as one of the most restraining environmental factors for agricultural crops, particularly vegetables, which accounts for significant crop losses [6]. Summer vegetables are sensitive to chilling temperature (0-15°C) throughout plant development i.e. seed germination, vegetative growth and reproduction. Low temperature stress affects the reproductive stages of plant with delayed flowering which makes the pollen sterile that severely affects the crop yield [6,7]. Low temperature stress also limits the agricultural productivity of plants in hilly areas and has a major impact on the survival and geographical distribution of the plants. The plant growth and crop productivity gets disturbed which results in substantial crop failure [8]. Low temperature induced change in membrane fluidity is one of the immediate consequences in plants during low temperature stress and might represent a potential site of perception and/or injury [9]. It is well documented that freeze-induced production of reactive oxygen species contributes to membrane damage and that intercellular ice can form adhesions with cell walls and membranes and cause cell rupture [10]. As temperatures drops below 0ºC, ice formation is generally initiated in the intercellular spaces in the extracellular fluid having a higher freezing point (lower solute concentration) than the intracellular fluid [11]. Low temperature stress during Alleviation of cold stress in vegetable crops Abdul Rasool Atayee* and Mohammad Safar Noori Faculty of Agriculture, Takhar University, Afghanistan ABSTRACT Low temperature is a major environmental factor that limits crop productivity of plants. Cold stress is a serious threat to the sustainability of crop yields. Low temperature has a huge impact on the survival and geographical distribution of plants. It negatively affects cellular components and metabolism, and temperature extremes impose stresses of variable severity that depend on the intensity and duration of the stress. Low temperature (less than minimum) leads to chlorosis, necrosis, membrane damage, changes in cytoplasm viscosity, and changes in enzyme activities leading to death of plant. Cold stress disrupts the integrity of intracellular organelles, leading to the loss of compartmentalization. It also causes reduction and impairing of photosynthesis, protein assembly and general metabolic processes. Moreover, cold stress during anthesis induces flower dropping, sterility of pollen, pollen tube distortion, ovule abortion and reduced fruit set, which leads to declined growth and lower yield. A number of approaches are being used to mitigate the deleterious effects of cold stress which threatens the successful vegetable crop production, application of plant growth regulators (salicylic acid, abscisic acid, jasmonic acid, Gibberellin and brassinosteroids) and unitization of genetics tools and plant breeding is one of the strategies to alleviate the low temperature stress in vegetable crops. Plant growth regulators play a greater role in improving the cold stress tolerance. In this paper, the effects of cold stress on vegetable growth, productivity and physiological activities were discussed, and some effective techniques for the mitigation of cold stress that help sustainable vegetable production under fluctuating climate is presented. KEYWORDS: Cold stress, Alleviation, plant growth regulators, vegetable, genetic tools Copyright: © The authors. This article is open access and licensed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted, use, distribution and reproduction in any medium, or format for any purpose, even commercially provided the work is properly cited. Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. Received: Feb 11, 2020 Accepted: May 13, 2020 Published: May 18, 2020 *Corresponding author: Abdul Rasool Atayee E-mail: abdulrasool. atayee2018@gmail.com ISSN: 2184-0261 Review Article