Identification, characterization of Apyrase (APY) gene family in rice (Oryza sativa) and analysis of the expression pattern under various stress conditions.

Apyrase (APY) is a nucleoside triphosphate (NTP) diphosphohydrolase (NTPDase) which is a member of the superfamily of guanosine diphosphatase 1 (GDA1)-cluster of differentiation 39 (CD39) nucleoside phosphatase. Under various circumstances like stress, cell growth, the extracellular adenosine triphosphate (eATP) level increases, causing a detrimental influence on cells such as cell growth retardation, ROS production, NO burst, and apoptosis. Apyrase hydrolyses eATP accumulated in the extracellular membrane during stress, wounds, into adenosine diphosphate (ADP) and adenosine monophosphate (AMP) and regulates the stress-responsive pathway in plants. This study was designed for the identification, characterization, and for analysis of APY gene expression in Oryza sativa. This investigation discovered nine APYs in rice, including both endo- and ecto-apyrase. According to duplication event analysis, in the evolution of OsAPYs, a significant role is performed by segmental duplication. Their role in stress control, hormonal responsiveness, and the development of cells is supported by the corresponding cis-elements present in their promoter regions. According to expression profiling by RNA-seq data, the genes were expressed in various tissues. Upon exposure to a variety of biotic as well as abiotic stimuli, including anoxia, drought, submergence, alkali, heat, dehydration, salt, and cold, they showed a differential expression pattern. The expression analysis from the RT-qPCR data also showed expression under various abiotic stress conditions, comprising cold, salinity, cadmium, drought, submergence, and especially heat stress. This finding will pave the way for future in-vivo analysis, unveil the molecular mechanisms of APY genes in stress response, and contribute to the development of stress-tolerant rice varieties.

Ectopic expression of Vigna radiata's vacuolar Na+/H+ antiporter gene (VrNHX1) in indica rice (Oryza sativa L.).

It is essential to develop high salt-tolerant rice varieties in order to cultivate the salt-affected lands. In this study, Na+/H+ exchanger 1 (NHX1) gene isolated from Vigna radiata L. Wilczek was transferred in Bangladesh Rice Research Institute (BRRI) developed two indica rice genotypes BRRI Dhan28 and BRRI Dhan29 using in-planta approach for improvement of salinity tolerance. Embryonic axes of matured dehusked rice seeds were injured and co-cultivated with Agrobacterium strain harboring VrNHX1 gene and finally regenerated. GUS histochemical assay and PCR amplification of GUS-a and VrNHX1 were performed to confirm the transformation. Expression confirmation was done by semi-quantitative RT-PCR. Under salinity stress, transgenic lines showed higher chlorophyll, relative water content and decreased electrolyte leakage, proline content, lipid peroxidation level, and catalase enzyme activity which represent the better physiology than control plants. Moreover, under salinity stress (150 mM), transgenic lines exhibited superior growth and salt tolerant than non-transgenic plants.

Genome wide analysis of the heavy-metal-associated (HMA) gene family in tomato and expression profiles under different stresses.

The heavy-metal-associated (HMA) family plays a major role in the transportation of metals. Despite having the genome sequence of the tomato (Solanum lycopersicum), the HMA gene family has not been studied yet. In this study, we identified 48 HMA genes and categorized them into Cu/Ag P1B-ATPase and Zn/Co/Cd/Pb P1BATPase sub-families according to their phylogenic relationship with Arabidopsis and rice. The SlHMA genes were distributed throughout the 12 chromosomes. Analysis of gene structure, chromosomal position, and synteny, revealed that segmental duplications bestowed their evolution. The high numbers of stress-related cis-elements were found to be present in the putative promoter regions indicate the involvement of SlHMAs in stress modulation pathways. RNA-seq data revealed that SlHMAs had divergent expression in different tissues and developmental stages, where members of Cu/Ag P1B-ATPase subfamily were strongly expressed in the roots. RT-qPCR analysis of nine selected SlHMAs showed that most of the genes were up-regulated in response to heavy metals and moderately regulated in response to different abiotic stresses such as salt, drought, and cold.

Effect of saccharides on secondary compounds production from stem derived callus of Datura inoxia.

Datura inoxia is a subshrub plant known for its toxicity which results from the presence of the tropane alkaloid scopolamine and hyoscyamine. Saccharides are one of the most important elicitors that can alter physiological and biochemical responses in plants. This study targeted to increase the production of secondary metabolites in Datura inoxia avoiding genetic alteration and processes using different nontoxic and biodegradable compounds, utilizing calli induced from Datura inoxia stems to observe the effects of mannitol and sorbitol on the production of the two major secondary metabolites, scopolamine and hyoscyamine. Methanolic extract of the whole plant and callus was used to examine the production of two secondary metabolites in Datura inoxia using HPLC in a qualitative and quantitative manner which revealed the increased production of scopolamine and hyoscyamine in calli. The addition of mannitol and sorbitol in the media had a negative effect on both the fresh and dry weight of the calli but production of scopolamine and hyoscyamine increased significantly. In-vitro anti-microbial assay of hyoscyamine against Escherichia coli ATCC25922 and Candida albicans resulted in total inhibition of both the microbes in concentrations as low as 200 µg/ml.