Anthocyanins Are Key Regulators of Drought Stress Tolerance in Tobacco

Abstract

Abiotic stresses will be one of the major challenges for worldwide food supply in the near future. Therefore, it is important to understand the physiological mechanisms that mediate plant responses to abiotic stresses. When subjected to UV, salinity or drought stress, plants accumulate specialized metabolites that are often correlated with their ability to cope with the stress. Among them, anthocyanins are the most studied intermediates of the phenylpropanoid pathway. However, their role in plant response to abiotic stresses is still under discussion. To better understand the effects of anthocyanins on plant physiology and morphogenesis, and their implications on drought stress tolerance, we used transgenic tobacco plants (AN1), which over-accumulated anthocyanins in all tissues. AN1 plants showed an altered phenotype in terms of leaf gas exchanges, leaf morphology, anatomy and metabolic profile, which conferred them with a higher drought tolerance compared to the wild-type plants. These results provide important insights for understanding the functional reason for anthocyanin accumulation in plants under stress.

Comparing Machine Learning Methods for Classifying Plant Drought Stress from Leaf Reflectance Spectra in Arabidopsis thaliana

“…Anthocyanins are a class of different non-photosynthetic water-soluble pigments derived from flavonoids via the shikimic acid pathway [17]. Their biosynthesis is elicited by a number of abiotic stresses, including drought stress [45]. They may function as a screen to increase photoprotection and as a pool of antioxidant metabolites [46].…”

Divergent Leaf Morpho-Physiological and Anatomical Adaptations of Four Lettuce Cultivars in Response to Different Greenhouse Irradiance Levels in Early Summer Season

“…The LMA was evaluated on nine leaves per treatment as the ratio between leaf DW and leaf area. The number of epidermal cells and stomata were determined on the abaxial and adaxial sides of the same leaves used for leaf gas exchange and LMA measurements, as described by Cirillo et al [68]. Briefly, leaf impressions were made using cyanoacrylate glue on a microscopy slide.…”

The Effects of Salinity on the Anatomy and Gene Expression Patterns in Leaflets of Tomato cv. Micro-Tom

“…Anthocyanins act in stress response by increasing the solute content in the vacuoles thereby lowering the osmotic potential of the leaf [27]. Additionally, it was shown that anthocyanins' accumulation led to a metabolic shift in leaves with respect to amino acids and non-structural carbohydrates: proline content increased together with starch reserves' use to provide carbon skeletons required for the synthesis of metabolites involved in osmotic adjustment [28]. With an increasing salt concentration, a purple coloration started to develop rapidly in the epidermal layer of the abaxial side of leaves (Figure 2).…”