Impact of Water Deficit Stress on Brassica Crops: Growth and Yield, Physiological and Biochemical Responses

Abstract

Drought including both meteorological drought and water deficiency stress conditions is a major constraint on global agricultural productivity, particularly affecting Brassica species, which are vital oilseed and vegetable crops. As climate change intensifies, understanding plant responses to drought is crucial for improving drought resilience. Drought stress impacts Brassica crops at multiple levels, reducing germination rates, impairing physiological functions such as photosynthesis and water-use efficiency, and triggering oxidative stress due to the accumulation of reactive oxygen species. To counteract these effects, Brassica plants employ various adaptive mechanisms, including osmotic adjustment, antioxidant defense activation, and hormonal regulation. Recent research has explored molecular and physiological pathways involved in drought tolerance, revealing key physiological changes and biochemical markers that could be targeted for crop improvement. This review summarizes the latest findings on the physiological, biochemical, and molecular responses of Brassica crops to drought stress, with an emphasis on adaptive mechanisms and potential drought mitigation strategies. Additionally, future research directions are proposed, focusing on integrating molecular and agronomic approaches to enhance drought resilience in Brassica species.

Keywords: Brassica; climate change; drought; mechanisms; photosynthesis; tolerance; water deficit stress.

Figure 1

Impact of water deficit stress on sequential germination stages in Brassica crops [41,42,43,44,45,46,47,48]. (Created with Biorender.com).

Figure 2

Schematic representation of the physiological and biochemical responses of Brassica crops under water deficiency stress conditions [33,55,56,57,58,59,60,61,62,63,64,65,66]. (Created with Biorender.com).

Figure 3

Percentage yield loss in major Brassica crops under drought stress conditions. For cauliflower, the yield reduction was estimated by interpolating the reported “40–60% reduction” to midpoint for graphing. This figure was created from data presented by [35,58,86,88,94,95].