Osmotic adjustment is a prime drought stress adaptive engine in support of plant production

Abstract

Osmotic adjustment (OA) and cellular compatible solute accumulation are widely recognized to have a role in plant adaptation to dehydration mainly through turgor maintenance and the protection of specific cellular functions by defined solutes. At the same time, there has been an ongoing trickle of skepticism in the literature about the role of OA in supporting crop yield under drought stress. Contrarian reviews argued that OA did not sustain turgor or that it served mainly for plant survival rather than productivity. This critical review examined 26 published studies where OA was compared with yield under drought stress in variable genotypes of 12 crops, namely, barley, wheat, maize, sorghum, chickpea, pea, pigeon pea, soybean, canola, mustard, castor bean and sunflower. Over all crops a positive and significant association between OA and yield under drought stress were found in 24 out of 26 cases. Considering that it is generally difficult to find a singular plant trait responsible for yield advantage of numerous crops under different drought stress conditions, this evidence is no less than remarkable as proof that OA sustains crop yield under drought stress.

Effects of atmospheric and soil water status on photosynthesis and growth in tomato

“…For adaptation to dehydration, plants tend to maintain turgor by osmotic adjustment (Blum 2017). In this study, stomatal aperture and Ψ p decreased due to leaf dehydration under drought stress, and Ψ π was reduced to maintain turgor.…”

ABA Accumulation in Dehydrating Leaves Is Associated with Decline in Cell Volume, Not Turgor Pressure

“…Identifying the mechanisms for cell responses as plants dehydrate is crucial for analyzing and predicting crop and ecosystem responses to climate change (Blum, 1996(Blum, , 2017Bartlett et al, 2016), for isolating the proteins and the genes underlying the responses (Christmann et al, 2013), and for the design of model plants and crops with increased water use efficiency and/or drought tolerance (e.g. Nemhauser and Torii, 2016;Yang et al, 2016).…”

Drought-stressed tomato plants trigger bottom-up effects on key mite pests

“…This might explain the absence of induction in the case of TR126. We did not observed significant differences in polyphenol oxidase activity, whose expression pattern has been shown to vary depending on both the duration of plant exposure to drought stress and the infestation by different mite species (Ximénez-Embún et al, 2016, 2017.…”

“…Osmotic adjustment is a key factor in drought stress tolerance that allows plants to maintain turgor and keep normal cell activity (Bartels and Sunkar, 2005;Blum, 2017). It involves the accumulation of osmolites, mainly soluble carbohydrates and amino acids, facilitating water uptake and retention, and protecting and stabilizing macromolecules and structures from damage induced by stress conditions.…”

“…It has also been reported as an indicator of drought stress tolerance on tomato plant varieties, which showed reduced stomatal conductance . By closing stomata, the pathway through which atmospheric CO2 enters the leaf is also restricted, affecting photosynthesis Osmotic adjustment is a key factor in drought stress tolerance that allows plants to maintain turgor and keep normal cell activity (Bartels and Sunkar, 2005;Blum, 2017). It involves the accumulation of osmolites, mainly soluble carbohydrates and amino acids, facilitating water uptake and retention, and protecting and stabilizing macromolecules and structures from damage induced by stress conditions.…”