Role of miRNAs on Improving Salt Stress Tolerance of Chickpea
Authors: Nimmy.M.S, Vinod Kumar, Era Vaidya Malhotra and Lal bahadur singh
Chickpea (Cicer arietinum L.) is the second largest produced grain legume in the world contributing in supplying high quality dietary protein and fixing atmospheric nitrogen biologically. Mostly grown in arid and semi-arid areas, India is the largest producer of chickpea in the world with an estimated production of 7.17 Mt from an area of 8.6 Mha (FAOSTAT, 2015) and accounts for over 67.4 % of the total world production. Although chickpea production potential is high, it has not been fully realized owing to several abiotic stresses of which salinity is one of the major factors. Chickpea is a salt-sensitive crop species and soil salinity impedes chickpea production in many parts of the world, including large areas of farming land in India. It is reported that salinity alone affects 20% of the irrigated lands of the world. Finally, salt stress is expected to be an increasingly important constraint in near future due to climate change and global warming. The development of salt-tolerant chickpea cultivars is one of the major priorities currently for the researchers. The ultimate aim of salinity tolerance research is to increase the ability of plants to maintain growth and productivity in saline soils relative to their growth in non-saline soils.
MicroRNAs (miRNAs) are small regulatory RNAs (20-22 nt) known to be important regulators of gene expression in all organisms. Role of miRNAs in stress responses could be linked from the discovery that biotic and abiotic stress can modulate miRNA levels, together with the alteration in expression level of stress-associated genes as miRNA targets. In plants, functional analysis has demonstrated that several miRNAs play vital roles in plant resistance to abiotic and biotic stress (Sunkar and Zhu 2004). With the advancement of genomics tools and methods to identify novel miRNAs in various plant species, the number of miRNAs associated with salt stress response is increasing. The effects of miRNAs on improving plant abiotic stress tolerance were recently confirmed in rice and Arabidopsis by altering the miRNA expression in transgenic plants (Shriram et al.,2016).
Chickpea is an important source of protein in the vegetarian diet and productivity of the crop is negatively affected by salinity. Innovative research and development in agricultural technologies will be crucial to address the challenges faced by chickpea cultivation. Understanding the mechanism of miRNAs in regulating the tolerance of chickpea grown under salt stress through their specific target genes will be of immense importance in developing salt tolerant chickpea
Identification of salt responsive miRNAs and their target genes will offer an opportunity to better understand the regulatory pathways of chickpea plants during salt stress which can be further used for development of salt tolerant chickpea genotypes. Given that miRNAs are crucial components in gene regulatory networks, it is certain that a complete understanding of the functions of miRNAs will greatly increase our understanding of plant tolerance to salt stress
1. FAOSTAT (2015) http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID=567
2. Sunkar R, Zhu JK (2004) Novel and stress-regulated microRNAs and other small RNAs from Arabidopsis. Plant Cell 16:2001-2019
3. Varsha Shriram, Vinay Kumar, Rachayya M. Devarumath, Tushar S. Khare, Shabir H. Wani. (2016). MicroRNAs as potential targets of abiotic stress tolerance in plants. Front Plant Sci. ; 7: 817. doi: 10.3389/fpls.2016.00817
About Author / Additional Info:
Scientist at NRCPB, New Delhi.