Relationships between leaf morpho‐anatomy, water status and cell membrane stability in leaves of wheat seedlings subjected to severe soil drought

Abstract

The impact of the genotype‐specific leaf morphological and anatomical characteristics on the ability of wheat plants to preserve leaf water balance and cell membranes stability under drought stress was investigated. Seedlings of six modern semi‐dwarf (carriers of Rht, Reduced height genes) and six old tall bread wheat varieties were subjected to soil drought by withholding watering for 6 days. Morpho‐anatomical traits (leaf area, perimeter, thickness, stomata and trichome density) of daily watered (control) plants were characterized by light microscopy, scanning and image analyses. The leaf water status in both control and stressed plants was determined by measuring the relative water content (RWC). The leaf cell membranes stability in stressed plants was estimated by conductometric determination of the membranes injury index. On average, the modern semi‐dwarf varieties had less leaf area and leaf perimeter, and less dissection index, a parameter characterizing the leaf shape. Under drought stress, the modern genotypes maintained better water balance evidenced by significantly higher leaf RWC and better‐preserved the cell membranes stability supported by significantly lower Injury index. The correlations between morpho‐anatomical traits in control plants and drought tolerance‐related traits showed that the higher the leaf dissection index (i.e. more oblong leaves), the greater the water loss and the leaf membrane damages after desiccation were. The effect of shape of the evaporating surface on the water loss was modelled using wet filter paper. Similar to plant leaves, the evaporation and, respectively, water loss from paper pieces of more oblong shape (i.e. higher dissection index) was more intensive. The elucidation of the impact of the leaf shape on transpiration might contribute to better understanding of the mechanisms used by plants to maintain water reserves during drought stress and could be a basis for developing of simple and fast screening methods aiding the selection of drought tolerant genotypes.

Can Genetic Progress for Drought Tolerance in Popcorn Be Achieved by Indirect Selection?

“…Variation in corn leaf temperature in response to drought is closely related to biomass accumulation [37]. Under water stress conditions, higher leaf temperatures provide reduced transpiration as a water-saving strategy, which results in low relative leaf water content [46] and low cell membrane stability, supported by a significantly higher injury rate [47]. According to Zia et al (2013) [10], the lower canopy temperature along with a satisfactory grain yield is probably associated with a more efficient or more developed, i.e., deeper root system.…”

Photosynthetic and ascorbate-glutathione metabolism in the flag leaves as compared to spikes under drought stress of winter wheat (Triticum aestivum L.)

“…Drought has become the most important threat limiting plant growth, development, and crop production [ 1 – 4 ]. In recent years, crop production is challenged with frequently occurring drought periods around the world’s arid regions.…”

Severe Water Deficiency during the Mid-Vegetative and Reproductive Phase has Little Effect on Proso Millet Performance

“…The reason for the same or even higher F v /F m measured in vital leaves in the SWS group may also be a reduction in assimilation areas, which assures a sufficient amount of resources (elements and water) for the remaining leaves under extreme conditions. In addition, the comparable leaf function in all treatments may be a consequence of changes in the leaf morphology parameters, including the leaf thickness, stomata density, cuticle structure [68], and the shape of leaves [13]. In grass leaves, Si can be deposited right beneath the cuticle, therefore the water loss through the cuticle might also be reduced by this deposition of Si [69].…”

“…In addition, understanding plant strategies to cope with drought is becoming more and more important. Plants have evolved a variety of morphological and physiological adaptations to resist drought and thus to preserve optimal relative water content in their tissues [12,13]. The accumulation of silicon (Si) in plant tissues can increase plant resistance against various abiotic and biotic constraints, including water shortage [14,15].…”