Browsing by Author "Chaudhuri, Abira"

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Abiotic stress tolerance in plants: Brassinosteroids navigate competently
(MDPI AG, 2022) Chaudhuri, Abira; Halder, Koushik; Abdin, Malik Z; Majee, Manoj; Datta, Asis
Brassinosteroid hormones (BRs) multitask to smoothly regulate a broad spectrum of vital physiological processes in plants, such as cell division, cell expansion, differentiation, seed germination, xylem differentiation, reproductive development and light responses (photomorphogenesis and skotomorphogenesis). Their importance is inferred when visible abnormalities arise in plant phenotypes due to suboptimal or supraoptimal hormone levels. This group of steroidal hormones are major growth regulators, having pleiotropic effects and conferring abiotic stress resistance to plants. Numerous abiotic stresses are the cause of significant loss in agricultural yield globally. However, plants are well equipped with efficient stress combat machinery. Scavenging reactive oxygen species (ROS) is a unique mechanism to combat the deleterious effects of abiotic stresses. In light of numerous reports in the past two decades, the complex BR signaling under different stress conditions (drought, salinity, extreme temperatures and heavy metals/metalloids) that drastically hinders the normal metabolism of plants is gradually being untangled and revealed. Thus, crop improvement has substantial potential by tailoring either the brassinosteroid signaling, biosynthesis pathway or perception. This review aims to explore and dissect the actual mission of BRs in signaling cascades and summarize their positive role with respect to abiotic stress tolerance.
A calmodulin like EF hand protein positively regulates oxalate decarboxylase expression by interacting with E-box elements of the promoter
(Nature Publishing Group, 2015) Kamthan, Ayushi; Kamthan, Mohan; Kumar, Avinash; Sharma, Pratima; Ansari, Sekhu; Thakur, Sarjeet Singh; Chaudhuri, Abira; Datta, Asis
Oxalate decarboxylase (OXDC) enzyme has immense biotechnological applications due to its ability to decompose anti-nutrient oxalic acid. Flammulina velutipes, an edible wood rotting fungus responds to oxalic acid by induction of OXDC to maintain steady levels of pH and oxalate anions outside the fungal hyphae. Here, we report that upon oxalic acid induction, a calmodulin (CaM) like protein-FvCaMLP, interacts with the OXDC promoter to regulate its expression. Electrophoretic mobility shift assay showed that FvCamlp specifically binds to two non-canonical E-box elements (AACGTG) in the OXDC promoter. Moreover, substitutions of amino acids in the EF hand motifs resulted in loss of DNA binding ability of FvCamlp. F. velutipes mycelia treated with synthetic siRNAs designed against FvCaMLP showed significant reduction in FvCaMLP as well as OXDC transcript pointing towards positive nature of the regulation. FvCaMLP is different from other known EF hand proteins. It shows sequence similarity to both CaMs and myosin regulatory light chain (Cdc4), but has properties typical of a calmodulin, like binding of 45Ca2+, heat stability and Ca2+ dependent electrophoretic shift. Hence, FvCaMLP can be considered a new addition to the category of unconventional Ca2+ binding transcriptional regulators.
Chromatin-based transcriptional reprogramming in plants under abiotic stresses
(MDPI AG, 2022) Halder, Koushik; Chaudhuri, Abira; Abdin, Malik Z.; Majee, Manoj; Datta, Asis
Plants’ stress response machinery is characterized by an intricate network of signaling cascades that receive and transmit environmental cues and ultimately trigger transcriptional reprogramming. The family of epigenetic regulators that are the key players in the stress-induced signaling cascade comprise of chromatin remodelers, histone modifiers, DNA modifiers and regulatory noncoding RNAs. Changes in the histone modification and DNA methylation lead to major alterations in the expression level and pattern of stress-responsive genes to adjust with abiotic stress conditions namely heat, cold, drought and salinity. The spotlight of this review falls primarily on the chromatin restructuring under severe abiotic stresses, crosstalk between epigenetic regulators along with a brief discussion on stress priming in plants.
Classification of CRISPR/Cas system and its application in tomato breeding
(Springer Nature Publishing AG, 2022) Chaudhuri, Abira; Halder, Koushik; Datta, Asis
Remarkable diversity in the domain of genome loci architecture, structure of effector complex, array of protein composition, mechanisms of adaptation along with difference in pre-crRNA processing and interference have led to a vast scope of detailed classification in bacterial and archaeal CRISPR/Cas systems, their intrinsic weapon of adaptive immunity. Two classes: Class 1 and Class 2, several types and subtypes have been identified so far. While the evolution of the effector complexes of Class 2 is assigned solely to mobile genetic elements, the origin of Class 1 effector molecules is still in a haze. Majority of the types target DNA except type VI, which have been found to target RNA exclusively. Cas9, the single effector protein, has been the primary focus of CRISPR-mediated genome editing revolution and is an integral part of Class 2 (type II) system. The present review focuses on the different CRISPR types in depth and the application of CRISPR/Cas9 for epigenome modification, targeted base editing and improving traits such as abiotic and biotic stress tolerance, yield and nutritional aspects of tomato breeding.
Evaluation of the parameters affecting agrobacterium-mediated transformation process to produce cold stress-tolerant tomato by targeting Solanum lycopersicumC-repeat binding factor 2 gene
(Springer Nature Publishing AG, 2026) Halder, Koushik; Chaudhuri, Abira; Abdin, Malik Z.; Datta, Asis
C-repeat binding factors (CBFs) are a part of the AP2/ERF superfamily of transcription factors, which are known to regulate gene expression under different abiotic stress conditions, especially cold. In this study, when tomato cultivar Pusa Ruby (PR) was subjected to cold stress at 4 °C for 24 h, SlCBF2, along with SlCBF1, was found to be simultaneously induced at the early hours (3rd to 24th) of cold exposure. Similar simultaneous induction observed in another tomato variety, Arka Rakshak (AR), at the 3rd hour post-cold exposure. This brief yet strong simultaneous induction of both SlCBF1 and SlCBF2 provides a new insight into the initial induction of CBFs in cold-stressed tomato, which was not previously reported in PR or AR. To elucidate the SlCBF2-mediated cold response in tomato, we have developed stable overexpression lines that showed better cold tolerance than the wild-type PR. We have also evaluated and optimized two important parameters in the Agrobacterium-mediated transformation process and reported an improved transformation efficiency of 28.33% using 1 mg/L zeatin alone and 25% using a combination of 2 mg/L BAP and 0.1 mg/L IAA. Considering the varying degree of transformation efficiency in PR, this optimization will surely be of interest to future researchers to generate stable tomato transgenic lines. However, further works such as generating stable mutant lines targeting SlCBF2 and studying how it reacts to cold-stress, whether SlCBF2 directly regulates SlCBF1 or other downstream cold-responsive genes would provide a more definitive framework for establishing SlCBF2 as an important cold-stress-related transcription factor in tomato.
Genetically modified (GM) crops: milestones and new advances in crop improvement
(Springer, 2016) Kamthan, Ayushi; Chaudhuri, Abira; Kamthan, Mohan; Datta, Asis
Genetically modified (GM) crops can act as powerful complement to the crops produced by laborious and time consuming conventional breeding methods to meet the worldwide demand for quality foods. GM crops can help fight malnutrition due to enhanced yield, nutritional quality and increased resistance to various biotic and abiotic stresses. However, several biosafety issues and public concerns are associated with cultivation of GM crops developed by transgenesis, i.e., introduction of genes from distantly related organism. To meet these concerns, researchers have developed alternative concepts of cisgenesis and intragenesis which involve transformation of plants with genetic material derived from the species itself or from closely related species capable of sexual hybridization, respectively. Recombinase technology aimed at site-specific integration of transgene can help to overcome limitations of traditional genetic engineering methods based on random integration of multiple copy of transgene into plant genome leading to gene silencing and unpredictable expression pattern. Besides, recently developed technology of genome editing using engineered nucleases, permit the modification or mutation of genes of interest without involving foreign DNA, and as a result, plants developed with this technology might be considered as non-transgenic genetically altered plants. This would open the doors for the development and commercialization of transgenic plants with superior phenotypes even in countries where GM crops are poorly accepted. This review is an attempt to summarize various past achievements of GM technology in crop improvement, recent progress and new advances in the field to develop improved varieties aimed for better consumer acceptance.
RNA interference for improving disease resistance in plants and its relevance in this clustered regularly interspaced short palindromic repeats-dominated era in terms of dsRNA-based biopesticides
(Frontiers Media S.A., 2022) Halder, Koushik; Chaudhuri, Abira; Abdin, Malik Z.; Majee, Manoj; Datta, Asis
RNA interference (RNAi) has been exploited by scientists worldwide to make a significant contribution in the arena of sustainable agriculture and integrated pest management. These strategies are of an imperative need to guarantee food security for the teeming millions globally. The already established deleterious effects of chemical pesticides on human and livestock health have led researchers to exploit RNAi as a potential agri-biotechnology tool to solve the burning issue of agricultural wastage caused by pests and pathogens. On the other hand, CRISPR/Cas9, the latest genome-editing tool, also has a notable potential in this domain of biotic stress resistance, and a constant endeavor by various laboratories is in progress for making pathogen-resistant plants using this technique. Considerable outcry regarding the ill effects of genetically modified (GM) crops on the environment paved the way for the research of RNAi-induced double-stranded RNAs (dsRNA) and their application to biotic stresses. Here, we mainly focus on the application of RNAi technology to improve disease resistance in plants and its relevance in today’s CRISPR-dominated world in terms of exogenous application of dsRNAs. We also focused on the ongoing research, public awareness, and subsequent commercialization of dsRNA-based biocontrol products.
Small RNAs in plants: recent development and application for crop improvement
(Frontiers Media S.A., 2015) Kamthan, Ayushi; Chaudhuri, Abira; Kamthan, Mohan; Datta, Asis
The phenomenon of RNA interference (RNAi) which involves sequence-specific gene regulation by small non-coding RNAs, i.e., small interfering RNA (siRNA) and microRNA (miRNA) has emerged as one of most powerful approaches for crop improvement. RNAi based on siRNA is one of the widely used tools of reverse genetics which aid in revealing gene functions in many species. This technology has been extensively applied to alter the gene expression in plants with an aim to achieve desirable traits. RNAi has been used for enhancing the crop yield and productivity by manipulating the gene involved in biomass, grain yield and enhanced shelf life of fruits and vegetables. It has also been applied for developing resistance against various biotic (bacteria, fungi, viruses, nematodes, insects) and abiotic stresses (drought, salinity, cold, etc.). Nutritional improvements of crops have also been achieved by enriching the crops with essential amino acids, fatty acids, antioxidants and other nutrients beneficial for human health or by reducing allergens or anti-nutrients. microRNAs are key regulators of important plant processes like growth, development, and response to various stresses. In spite of similarity in size (20–24 nt), miRNA differ from siRNA in precursor structures, pathway of biogenesis, and modes of action. This review also highlights the miRNA based genetic modification technology where various miRNAs/artificial miRNAs and their targets can be utilized for improving several desirable plant traits. microRNA based strategies are much efficient than siRNA-based RNAi strategies due to its specificity and less undesirable off target effects. As per the FDA guidelines, small RNA (sRNA) based transgenics are much safer for consumption than those over-expressing proteins. This review thereby summarizes the emerging advances and achievement in the field of sRNAs and its application for crop improvement.
Tweaking the small non-coding RNAs to improve desirable traits in plant
(MDPI AG, 2023) Halder, Koushik; Chaudhuri, Abira; Abdin, Malik Z; Datta, Asis
Plant transcriptome contains an enormous amount of non-coding RNAs (ncRNAs) that do not code for proteins but take part in regulating gene expression. Since their discovery in the early 1990s, much research has been conducted to elucidate their function in the gene regulatory network and their involvement in plants' response to biotic/abiotic stresses. Typically, 20-30 nucleotide-long small ncRNAs are a potential target for plant molecular breeders because of their agricultural importance. This review summarizes the current understanding of three major classes of small ncRNAs: short-interfering RNAs (siRNAs), microRNA (miRNA), and transacting siRNAs (tasiRNAs). Furthermore, their biogenesis, mode of action, and how they have been utilized to improve crop productivity and disease resistance are discussed here.