Intermittent moisture supply induces drought priming responses in some heat‐tolerant chickpea genotypes

Abstract

Heat and drought stresses are two abiotic factors that often occur simultaneously and are predicted to increase, consequently hampering plant growth. Response of different species to either stresses is well documented but information on the response of the same genotypes to both stresses in chickpea (Cicer arietinum L.) is limited. We aimed to determine whether previously noted heat‐stress‐tolerant genotype (Acc#7) is drought tolerant, that heat‐sensitive genotype (Acc#8) is drought sensitive, and whether intermittent moisture supply at vegetative stage would induce priming effect to later drought at flowering. At vegetative stage, plants were divided into three groups, nonstressed (watered to 75% field capacity [FC], severe water stress (moisture withholding for 14 d), and treated to 40% FC throughout the experiment (mild stress), with recovery for the severely stressed plants after which they were stressed (double stress) at flowering. Drought treatments at vegetative and flowering growth stages decreased physiological parameters and biomass accumulation in both genotypes except low water supply at 40% FC that decreased biomass in Acc#7 but not Acc#8. Double‐drought stress resulted in priming effect in Acc#7, having higher biomass, chlorophyll fluorescence, stomatal conductance (gs), net photosynthesis, and relative water content (RWC) vs. the introduction of stress only at flowering growth stage as well as in comparison with Acc#8. These results showed that both Acc#7 and Acc#8 are sensitive to drought, whereas after priming, Acc#7 is better acclimated to drought than Acc#8 associated with osmotic adjustment on leaf RWC and higher capacity to protect photosynthetic activity, making Acc#7 potentially ideal for areas associated with intermittent drought spells.

Drought-hardening improves drought tolerance in Nicotiana tabacum at physiological, biochemical, and molecular levels

“…On one hand, droughthardening treatments reduced the growth in both H and Y varieties in response to drought stress. The results of this study are in line with Makonya et al [31] as witnessed lower shoot biomass allocation in chickpea due to drought priming. While, on the other hand, drought-hardening improved the water uptake ability.…”

Natural Genotypic Variation Underpins Root System Response to Drought Stress in Bambara Groundnut [Vigna subterranea (L.) Verdc.]

“…Furthermore, changes in root length has been observed in rice under water stress, and has been linked to increased shoot biomass and yield ( Niones et al, 2013 ). The trend agrees with intensive studies on chickpea ( Yinglong et al, 2017 ; Makonya et al, 2020 ) and wheat ( Tolley and Mohammadi, 2020 ), which suggest that there is a persistent tendency of a positive correlation between roots and shoots. Since a plant is a biological entity, the root system absorbs water and nutrients for the stem and leaves, which then provide food for the root system’s maintenance.…”

Morphological and physiological responses of Calobota sericea plants subjected to water limitation and subsequent rewatering

“…In areas experiencing regular periods of water limitation, perennial plants, compared with annuals, have a greater diversity of physiological and/or biochemical responses, which allows them greater resistance to drought (Praba et al 2009;Perez-Harguindeguy et al 2013;Basu et al 2016). Generally, the mechanism of drought resistance in perennial plants include drought avoidance, drought tolerance or a combination of these adaptive responses (Praba et al 2009;Perez-Harguindeguy et al 2013;Basu et al 2016;Makonya et al 2020). Drought avoidance is the ability of plants to maintain relatively higher water content, despite reduced soil moisture content (Perez-Harguindeguy et al 2013;Basu et al 2016).…”