AUTHOR=Amin Atia B. , Rathnayake Kumudu N. , Yim Won C. , Garcia Travis M. , Wone Beate , Cushman John C. , Wone Bernard W. M. 

TITLE=Crassulacean Acid Metabolism Abiotic Stress-Responsive Transcription Factors: a Potential Genetic Engineering Approach for Improving Crop Tolerance to Abiotic Stress

JOURNAL=Frontiers in Plant Science

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00129

DOI=10.3389/fpls.2019.00129

ISSN=1664-462X

ABSTRACT=<p>This perspective paper explores the utilization of abiotic stress-responsive transcription factors (TFs) from crassulacean acid metabolism (CAM) plants to improve abiotic stress tolerance in crop plants. CAM is a specialized type of photosynthetic adaptation that enhances water-use efficiency (WUE) by shifting CO<sub>2</sub> uptake to all or part of the nighttime when evaporative water losses are minimal. Recent studies have shown that TF-based genetic engineering could be a useful approach for improving plant abiotic stress tolerance because of the role of TFs as master regulators of clusters of stress-responsive genes. Here, we explore the use of abiotic stress-responsive TFs from CAM plants to improve abiotic stress tolerance and WUE in crops by controlling the expression of gene cohorts that mediate drought-responsive adaptations. Recent research has revealed several TF families including <italic>AP2/ERF</italic>, <italic>MYB, WRKY, NAC</italic>, <italic>NF-Y</italic>, and <italic>bZIP</italic> that might regulate water-deficit stress responses and CAM in the inducible CAM plant <italic>Mesembryanthemum crystallinum</italic> under water-deficit stress-induced CAM and in the obligate CAM plant <italic>Kalanchoe fedtschenkoi</italic>. Overexpression of genes from these families in <italic>Arabidopsis thaliana</italic> can improve abiotic stress tolerance in <italic>A. thaliana</italic> in some instances. Therefore, we propose that TF-based genetic engineering with a small number of CAM abiotic stress-responsive TFs will be a promising strategy for improving abiotic stress tolerance and WUE in crop plants in a projected hotter and drier landscape in the 21st-century and beyond.</p>