Toward a smart skin: Harnessing cuticle biosynthesis for crop adaptation to drought, salinity, temperature, and ultraviolet stress

Abstract

Drought, salinity, extreme temperatures, and ultraviolet (UV) radiation are major environmental factors that adversely affect plant growth and crop production. As a protective shield covering the outer epidermal cell wall of plant aerial organs, the cuticle is mainly composed of cutin matrix impregnated and sealed with cuticular waxes, and greatly contributes to the plant adaption to environmental stresses. Past decades have seen considerable progress in uncovering the molecular mechanism of plant cutin and cuticular wax biosynthesis, as well as their important roles in plant stress adaptation, which provides a new direction to drive strategies for stress-resilient crop breeding. In this review, we highlighted the recent advances in cuticle biosynthesis in plant adaptation to drought, salinity, extreme temperatures, and UV radiation stress, and discussed the current status and future directions in harnessing cuticle biosynthesis for crop improvement.

Ultraviolet Radiation and Its Effects on Plants

“…Exposure to UV radiation-induced deposition of wax in plants of species, such as Coffea arabica, Coffea canephora, Hordeum vulgare, Cucumis sativus, and Phaseolus vulgaris, which results in an increase in the thickness of the cuticle. Additionally, molecules such as phenolic acids and flavonoids can accumulate in the cuticle, functioning as photoprotectors against UV light or as UV light attenuators, respectively [17].…”

“…Photosynthesis is a light-dependent process, so it is almost inevitable that it be affected by the presence of UV radiation. There are several reports about the damage caused by UV radiation in specific sites of the photosynthetic apparatus of green plants (Figure 1A) [17]. Much of the damage is caused by the enhanced production of reactive oxygen species (ROS) that are involved in UV-induced responses, both as signaling agents within normal cellular processes and as damaging agents.…”

Exploring and exploiting cuticle biosynthesis for abiotic and biotic stress tolerance in wheat and barley

“…By limiting non-stomatal water loss, cuticle contributes to plant adaptation to drought conditions, which has been extensively discussed in previous reviews ( Xue et al., 2017 ; Lewandowska et al., 2020 ; Liu et al., 2022b ). Upregulation of cuticle biosynthesis-related genes such as CER1s , FARs , SHN1 , MYB74 , WXPLs in response to drought stress has been reported in wheat and barley ( Wang et al., 2015 ; Bi et al., 2016 ; Wang M. et al, 2016 ; Bi et al., 2017 ; Bi et al., 2018 ; Chai et al., 2018 ; Li et al., 2019 ; He et al., 2022 ).…”

“…As an advanced genome editing (GE) technique, the CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR associated 9) system has been extensively employed for functional genomics and trait improvement in model and crop plants ( Chen et al., 2019 ; Manghwar et al., 2019 ; Zhu et al., 2020 ; Gao, 2021 ). Knockout of MYS1 and MYS2 , transcription repressors of DECREASE WAX BIOSYNTHESIS ( DEWAX ), by CRISPR-Cas9 system, resulted in the reduced wax loads and attenuated plant drought tolerance, suggesting that genome editing of cuticle biosynthesis genes could effectively alter plant stress tolerance ( Liu et al., 2022c ). However, the conventional application of the CRISPR-Cas9 system necessitates plant transformation and regeneration, which hinders its use in wheat and barley breeding.…”

“…It has been demonstrated that the expression of cuticle biosynthesis genes is governed by DNA-binding transcription factors (TFs), mediators, and epigenetic regulators ( Lee and Suh, 2015 ; Lee and Suh, 2022 ). At the same time, there is increasing evidence that cuticle biosynthesis mechanisms could be exploited for crop improvement ( Wang et al., 2020 ; Liu et al., 2022b ). Although past decades have seen a great advance in the understanding mechanisms of plant cuticle biosynthesis, most of this progress was achieved in model plants.…”