Leaf Cuticular Wax, a Trait for Multiple Stress Resistance in Crop Plants

Abstract

Cuticular waxes form the primary interface between a plant and its external environment. The most important function of this hydrophobic interface is regulation of non-stomatal water loss, gas exchange and conferring resistance to a wide range of biotic as well as abiotic stresses. The biosynthesis, transport and deposition of the cuticular waxes are tightly coordinated by complex molecular networks, which are also often regulated in response to various developmental, biotic as well as abiotic cues. Evidences from model as well as non-model systems suggest that targeted manipulation of the molecular regulators of wax biosynthetic pathways could enhance plant resistance to multiple stresses as well as enhance the post-harvest quality of produce. Under the current scenario of varying climatic conditions, where plants often encounter multiple stress conditions, cuticular waxes is an appropriate trait to be considered for crop improvement programs, as any attempt to improve cuticular traits would be advantageous to the crop to enhance its adaptability to diverse adverse conditions. This chapter briefs on the significance of cuticular waxes in plants, its biosynthesis, transport and deposition, its implication on plant resistance to adverse conditions, and the current options in targeted manipulation of wax-traits for breeding new crop types.Abiotic and Biotic Stress in Plants 2 vegetative and reproductive growth. Some of the abiotic stresses such as drought, high temperature and salinity can influence the occurrence and spread of biotic agents like pathogens, insects, and weeds [1]. In crops like tomato, cucurbits and rice, temperature is one of the most important deciding factors for the occurrence of bacterial diseases [2]. Temperature can also alter the incidence of vector-borne diseases by modifying spread of vectors.But, in their natural environment, plants face combination of stresses, especially under the changing climate scenario. The effect of stresses would be more pronounced under combined (biotic and abiotic) stresses [3], while simultaneous occurrence of abiotic and biotic stresses are more destructive to crop production [4]. Hence, there exists a need now, to look for common traits that can contribute for plant adaptation to such multifarious stressful conditions and sustain crop productivity as well. In this scenario, it is desirable to have a single trait that can confer tolerance to multiple (abiotic and biotic) stresses. Cuticular waxes, a major component of plant cuticle covering all the aerial parts of the plants, can be considered as an important trait for combined stress resistance. Cuticular waxes: a component of plant cuticleThe cuticle is a unique structure developed by land plants during the course of their evolution from an aquatic to a terrestrial lifestyle [5]. The primary role of this lipophilic layer, comprising cutin and cuticular waxes, was to limit non-stomatal water loss by functioning as a physical barrier between the plant surface and its external environment [6]. Development of a...

How Machine Learning Methods Helped Find Putative Rye Wax Genes Among GBS Data

“…ABCG were also considered to be essential components of the plant immune system [ 86 ]. This is consistent with the observation that epicuticular waxes play roles in plant-insect interactions [ 87 , 88 ]. This aspect makes our putative gene an interesting research object in the context of rye resistance to pathogens.…”

Dissecting the Roles of Cuticular Wax in Plant Resistance to Shoot Dehydration and Low-Temperature Stress in Arabidopsis

“…A key innovation in the plant evolutionary history was the development of the cuticle with its cuticular waxes, the first line of physical barrier against any external factors [1][2][3]. Several studies have shown cuticular waxes play an important role in the plant's response to abiotic and biotic stresses [1,2,4,5]. Most importantly, its role in protection against nonstomatal water loss has been described extensively in both monocot and dicot plant species [2].…”

Distinct Preflowering Drought Tolerance Strategies of Sorghum bicolor Genotype RTx430 Revealed by Subcellular Protein Profiling

“…We observed a significant RTx430-specific 34-fold increase in 3-ketoacyl-CoA synthase (UniProt identifier A0A1B6PJK5), which catalyzes the first step in very-long-chain fatty acids (VLCFAs) necessary for epicuticular wax production [ 47 ]. Epicuticular wax is important for drought tolerance in multiple species [ 48 ], and its abundance in grass crops correlated with grain yield under drought stress [ 49 ], including sorghum [ 50 , 51 ]. Multiple drought-relevant proteins became significantly less abundant exclusively in organelle-enriched RTx430 during water deficit.…”