CsHTDb:Transcriptome based Cucumis sativus Database for Heat

Cucumis sativus

Agriculture and food safety are threatened by extreme climate change. High temperature (HT) stress restricts plant development and productivity and, in severe cases, even results in plant death. Due to global warming, vegetable crops in tropical and subtropical areas, including tomato, pepper, and cucumber experienced decreased fruit number, weight, and shape throughout spring and autumn. Abiotic stresses, such as drought stress on plants, will also be exacerbated by the high-temperature environment, which will also lead to the outbreak of several diseases. In particular, heat greatly affects plant growth and development, immunity and circadian rhythm, and poses a serious threat to the global food supply.

Cucumber

Cucumber is the annual vine crop is native to the Himalayan foothills. Cucumber is sensitive to high temperatures instead of its origin in tropical regions. For cucumber, the optimal temperature for its growth and development is 25-28 °C during the day and 15-20 °C at night. Cucumber plants in the early stage have become susceptible to heat stress (HS) with the increasing global temperature, especially during the late spring and early autumn cultivation, where the temperature often exceeds 35 °C. Besides during the summer season, the temperature of cultivation in open fields often exceeds 35 °C even during the seedling stage which leads to sunburn of leaves, growth retardation of stems and roots, and even plant death, which severely affects further growth of cucumber. In general, it is a crop that prefers a moderately warm environment, and the suitable temperature for growth is 20–30 °C and at a temperature above 35°C abnormal growth is very common. Heat-related damage to cucumbers causes the blooms to fall easily, the leaves to droop and turn yellow, and the fruit to become malformed. In more extreme situations, the heat can cause the vine to completely wither, the top to die, the blooms to wither, and the leaves to get burnt and wilted. To maintain life in high temperatures, plants have developed a variety of tolerance mechanisms. Physio-biochemical and molecular changes may be among these tactics among the standard stress management techniques. Understanding the molecular networks and identification of the differentially expressed genes (DEGs) in response to heat stress tolerance is key in developing genomic resources for use in breeding for heat tolerance. Besides, development of variants and molecular markers from the identified contrasting genetic resources will help in future marker assisted breeding programme in cucumber.