Browsing by Author "Rai, Vandna"

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CRISPR-Cas9 directed genome engineering for enhancing salt stress tolerance in rice
(Elsevier B.V., 2019) Farhat, Sufia; Jain, Neha; Singh, Nisha; Sreevathsa, Rohini; Dash, Prasanta K.; Rai, Rhitu; Yadav, Sandeep; Kumar, Pramod; Sarkar, Ananda K.; Jain, Ajay; Singh, Nagendra K.; Rai, Vandna
Crop productivity in rice is harshly limited due to high concentration of salt in the soil. To understand the intricacies of the mechanism it is important to unravel the key pathways operating inside the plant cell. Emerging state-of-the art technologies have provided the tools to discover the key components inside the plant cell for salt tolerance. Among the molecular entities, transcription factors and/or other important components of sensing and signaling cascades have been the attractive targets and the role of NHX and SOS1 transporters amply described. Not only marker assisted programs but also transgenic approaches by using reverse genetic strategies (knockout or knockdown) or overexpression have been extensively used to engineer rice crop. CRISPR/Cas is an attractive paradigm and provides the feasibility for manipulating several genes simultaneously. Here, in this review we highlight some of the molecular entities that could be potentially targeted for generating rice amenable to sustain growth under high salinity conditions by employing CRISPR/Cas. We also try to address key questions for rice salt stress tolerance other than what is already known.
Iron availability affects phosphate deficiency-mediated responses, and evidences of cross talk with auxin and zinc in Arabidopsis
(Oxford University Press, 2015) Rai, Vandna; Sanagala, Raghavendrarao; Sinilal, Bhaskaran; Yadav, Sandeep; Sarkar, Ananda K.; Dantu, Prem Kumar; Jain, Ajay
Phosphate (Pi) is pivotal for plant growth and development. Pi deficiency triggers local and systemically regulated adaptive responses in Arabidopsis thaliana. Inhibition of primary root growth (PRG) and retarded development of lateral roots (LRs) are typical local Pi deficiency-mediated responses of the root system. Expression of Pi starvation-responsive (PSR) genes is regulated systemically. Here, we report the differential influence of iron (Fe) availability on local and systemic sensing of Pi by Arabidopsis. P-Fe- condition disrupted local Pi sensing, resulting in an elongated primary root (PR). Altered Fe homeostasis in the lpsi mutant with aberration in local Pi sensing provided circumstantial evidence towards the role of Fe in the maintenance of Pi homeostasis. Reporter gene assays, expression analysis of auxin-responsive genes (ARGs) and root phenotyping of the arf7arf19 mutant demonstrated the role of Fe availability on local Pi deficiency-mediated LR development. In addition, Fe availability also exerted a significant influence on PSR genes belonging to different functional categories. Together, these results demonstrated a substantial influence of Fe availability on Pi deficiency-mediated responses of ontogenetically distinct traits of the root system and PSR genes. The study also provided evidence of cross-talk between Pi, Fe and Zn, highlighting a complex tripartite interaction amongst them for maintaining Pi homeostasis.
Role of abiotic stress responsive miRNAs in Arabidopsis root development
(Springer Nature Publishing AG, 2020) Singh, Archita; Gandhi, Nidhi; Mishra, Vishnu; Yadav, Sandeep; Rai, Vandna; Sarkar, Ananda K.
Abiotic stresses like drought, extreme temperature, and lack of sufficient water or nutrients adversely affect plant growth and productivity. The physiological responses of higher plants to the environmental stresses are largely influenced by the root system, which can quickly modulate its developmental pattern under changing water, nutrient, and temperature, as an adaptive response. Protein coding genes, phytohormones and microRNAs (miRNAs) are among the key players which imparts crucial intrinsic role in shaping the root development and its environment adaptive growth pattern. Among these factors, miRNAs belong to a class of small non-coding RNAs of 21–24 nucleotides in length, which regulates various aspects of plant growth and development by negatively regulating their target genes through either transcriptional cleavage or translational inhibition. Although many miRNAs have been identified to be differentially regulated under various abiotic stress conditions, only a limited number of them have been characterized, due to the complex nature of its regulation. However, some of the miRNAs, such as miR156, miR165/166, miR169 etc., have recently been shown to be involved in both abiotic stress response and root development, indicating the diverse role of miRNA mediated gene regulation. The field of miRNA mediated gene regulation is dynamically expanding and more miRNAs are being characterized for their function. Current review focuses on miRNAs that are differentially regulated by major abiotic stresses as well as are involved in root development in Arabidopsis thaliana. We highlight their role in regulation of multiple and diverse aspects of developmental and physiological processes in Arabidopsis.