The DEAD-box RNA helicases and multiple abiotic stresses in plants: a systematic review of recent advances and challenges

Major crop production does not yet match the population growth rate because multiple abiotic stresses hamper the growth and yield of these crops. Most of the plants can tolerate adverse climatic conditions by performing some adaptive machineries but to certain extent. Till date various biotechnological and molecular breeding research approaches have been directed towards developing resistance to single stress factor. However, development of crop plants resistant to a single stress is not an ideal solution in the current agriculture scenario. Occurrence of multiple stresses at a single point of time makes it difficult to formulate research strategies. Considering the huge loss of crop productivity due to these environmental factors, there is an urgent need to direct our research focus towards developing sustainable multi-stress resistance in plants to counter the adverse effect of climate change on the productivity of crops. RNA helicases are ubiquitous proteins that are found in both prokaryotes and eukaryotes. The largest RNA helicase family comprises the DEAD-box RNA helicases which are involved in many aspects of RNA metabolism and in diverse biological processes in plants including regulation of multiple abiotic stress responses. The DEAD-box RNA helicases can be considered as means to identify pathways involved in multiple abiotic stress tolerance. In this review, we summarize the recent advances in elucidating the functions of the DEAD-box RNA helicases in multiple abiotic stress responses and future challenges. We also briefly discussed about our recent research efforts (published and on-going) in this direction. This review would help to formulate new research endeavours utilizing the DEAD-box helicase genes in development of multiple abiotic stress tolerant plants through genetic engineering and biotechnology. Target specific multiplex and multigene CRISPR/Ca9 genome editing would be ideal approach to edit different abiotic stress responsive DEAD-box RNA helicase genes to develop sustainable multiple abiotic stress tolerance in crop plants.