Editorial: Systems Biology and Synthetic Biology in Relation to Drought Tolerance or Avoidance in Plants

Abstract

Drought stress has been a long-time limitation to crop production that is being exacerbated by climate change and associated reductions in the availability of blue water resources for agriculture. Most existing food and industrial crops are susceptible to drought stress, which can cause a significant loss in crop yield. Therefore, our ability to develop more climate-resilient crops that are more heat and drought tolerant will become increasingly important in the near future. In nature, plants have evolved two important mechanisms to overcome the effects of drought stress:(1) drought avoidance, which enables plants to maintain relatively high tissue water content in water-limited environments by minimizing water loss and optimizing water uptake, and (2) drought tolerance, which enables plants to endure low tissue water content by maintaining cell turgor (resulting from osmotic adjustment and cellular elasticity) and increasing protoplasmic resistance (Basu et al., 2016). With more and more genomics resources available for diverse plant lineages showing contrasting strategies and variation in drought avoidance or tolerance (Yin et al., 2014;Abraham et al., 2016;Yang et al., 2017;Chen et al., 2018), systems biology, which features genome-scale analysis of molecules and their interactions (Westerhoff and Palsson, 2004), is becoming a popular approach to link genes to drought-avoidance or drought-tolerance traits. Our knowledge about the genes associated with drought stress responses generated by systems biology research can inform the construction of libraries of biological parts for synthetic biology, which aims to design or re-design biological processes (Cook et al., 2014). Synthetic biology has great potential for creating genetically-modified plants with enhanced drought avoidance or tolerance De Paoli et al., 2014;Llorente et al., 2018). This Research Topic features three articles on the theme of systems biology of crassulacean acid metabolism (CAM) as a model strategy for plant adaptation to water-limited conditions and four articles related to genetic improvement of plant drought avoidance or tolerance using synthetic biology and genetic engineering approaches.

Osmoregulation and its actions during the drought stress in plants

“…They avoid drought with a reversed day/night stomatal movement compared to C3 or C4 photosynthesis plants and provide high water‐use efficiency (WUE) (Yang et al, 2015). The drought experienced in crop plants is mostly seasonal (Yang et al, 2020). In nature, facultative CAM plants can be induced by CAM photosynthesis when exposed to drought stress (Yang et al, 2019).…”

“…Similarly, over‐expression of a drought‐sensitive NAC family gene from Kalanchoe fedtschenkoi (KfNAC83) has revealed an increased resistance to water stress in A thaliana . It has also been shown that overexpression of the rice gene OsNAR2.1 , which encodes a nitrate transporter partner protein, has increased the drought tolerance in rice (Yang et al, 2020).…”

Plant Biosystems Design Research Roadmap 1.0

“…CAM engineering requires design of multiple gene modules involved in carboxylation, decarboxylation, and stomatal movement, as well as genes involved in leaf succulence and vacuole size [233][234][235]. Biosystems design approaches could be used to integrate these CAM-related gene modules into plants, preferably using gene circuits to establish drought-inducible CAM (or CAM-on-demand) systems [236].…”

Biological Parts for Engineering Abiotic Stress Tolerance in Plants

“…biology technologies [17,18]. Synthetic techniques for regulating gene expression and cellular processes, particularly chemically inducible systems, CRISPR/Cas9-based technologies, and other advancements in genome engineering, are critical for advancing plant synthetic biology in the future [12,[19][20][21].…”