Transcription elongation factor AtSPT4-2 positively modulates salt tolerance in Arabidopsis thaliana.

BACKGROUND: Salt stress significantly influences plant growth and reduces crop yield. It is highly anticipated to develop salt-tolerant crops with salt tolerance genes and transgenic technology. Hence, it is critical to identify salt tolerance genes that can be used to improve crop salt tolerance. RESULTS: We report that the transcription elongation factor suppressor of Ty 4-2 (SPT4-2) is a positive modulator of salt tolerance in Arabidopsis thaliana. AtSPT4-2 expression is induced by salt stress. Knockout mutants of AtSPT4-2 display a salt-sensitive phenotype, whereas AtSPT4-2 overexpression lines exhibit enhanced salt tolerance. Comparative transcriptomic analyses revealed that AtSPT4-2 may orchestrate the expression of genes associated with salt tolerance, including stress-responsive markers, protein kinases and phosphatases, salt-responsive transcription factors and those maintaining ion homeostasis, suggesting that AtSPT4-2 improves salt tolerance mainly by maintaining ion homeostasis and enhancing stress tolerance. CONCLUSIONS: AtSPT4-2 positively modulates salt tolerance by maintaining ion homeostasis and regulating stress-responsive genes and serves as a candidate for the improvement of crop salt tolerance.

Nanotechnologies for environmental remediation and their ecotoxicological impacts.

Environmental nanoremediation is an emerging technology that aims to rapidly and efficiently remove contaminants from the polluted sites using engineered nanomaterials (ENMs). Inorganic nanoparticles which are generally metallic, silica-based, carbon-based, or polymeric in nature serve to remediate through chemical reactions, filtration, or adsorption. Their greater surface area per unit mass and high reactivity enable them to treat groundwater, wastewater, oilfields, and toxic industrial contaminants. Despite the growing interest in nanotechnological solutions for bioremediation, the environmental and human hazard associated with their use is raising concerns globally. Nanoremediation techniques when compared to conventional remediation solutions show increased effectivity in terms of cost and time; however, the main challenge is the ability of ENMs to remove contaminants from different environmental mediums by safeguarding the ecosystem. ENMs improving the accretion of the pollutant and increasing their bioavailability should be rectified along with the vigilant management of their transfer to the upper levels of the food chain which subsequently causes biomagnification. The ecosystem-centered approach will help monitor the ecotoxicological impacts of nanoremediation considering the safety, sustainability, and proper disposal of ENMs. The environment and human health risk assessment of each novel engineered nanomaterial along with the regulation of life cycle assessment (LCA) tools of ENMs for nanoremediation can help investigate the possible environmental hazard. This review focuses on the currently available nanotechnological methods used for environmental remediation and their potential toxicological impacts on the ecosystem.

Transporters and transcription factors gene families involved in improving nitrogen use efficiency (NUE) and assimilation in rice (Oryza sativa L.).

Nitrogen (N) as a macronutrient is an important determinant of plant growth. The excessive usage of chemical fertilizers is increasing environmental pollution; hence, the improvement of crop's nitrogen use efficiency (NUE) is imperative for sustainable agriculture. N uptake, transportation, assimilation, and remobilization are four important determinants of plant NUE. Oryza sativa L. (rice) is a staple food for approximately half of the human population, around the globe and improvement in rice yield is pivotal for rice breeders. The N transporters, enzymes indulged in N assimilation, and several transcription factors affect the rice NUE and subsequent yield. Although, a couple of improvements have been made regarding rice NUE, the knowledge about regulatory mechanisms operating NUE is scarce. The current review provides a precise knowledge of how rice plants detect soil N and how this detection is translated into the language of responses that regulate the growth. Additionally, the transcription factors that control N-associated genes in rice are discussed in detail. This mechanistic insight will help the researchers to improve rice yield with minimized use of chemical fertilizers.

Combined application of two Bacillus species enhance phytoremediation potential of Brassica napus in an industrial metal-contaminated soil.

This study aimed to assess the impact of individual as well as combined application of Lysinibacillus macroides and Bacillus safensis in phytoremediation potential of Brassica napus grown in soil contaminated by industrial effluents. In response to five metals; copper, chromium, nickel, lead, and cadmium, results revealed that germination percentage, fresh and dry weights, and photosynthetic pigments of B. napus decreased under contaminated soil. On the other hand, electrolyte leakage due to cellular injury, metabolites (proline and glycine betaine), antioxidant enzymes (superoxide dismutase, catalase, peroxidase, ascorbate peroxidase), accumulation of hydrogen peroxide and metals in plant's roots, shoots and leaves increased. Inoculation significantly reduced these effects as proved by the enhancement of germination percentage, fresh and dry biomass, and photosynthetic pigments. Simultaneously, the antioxidant enzymes, metabolites contents (proline and glycine betaine) and metal concentrations in plant's roots, shoots and leaves decreased. Combined application of both Bacilli strains was found more effective as compared to individual inoculation. It was concluded that metal resistant Bacillus species in combination had growth effects on B. napus and enhanced its phytoremediation efficiency in contaminated soil.Novelty statementBrassica napus; a hyper-accumulator of metals, loses phytoremediation potential with the passage of growth. Two Bacillus species (Lysinibacillus macroides and Bacillus safensis) having known bioremediation abilities were employed individually as well as in combination under metals contaminated soil to increase phytoremediation efficiency of B. napus. The metals containing soil used is a unique aspect in this study because selected soil, contaminated by industrial effluents, has not been evaluated or reported earlier. Combined application of Bacilli improved phytoremediation potential of B. napus more as compared to application of individual Bacillus strain which is yet another unique aspect of this investigation.

Loss of rice PARAQUAT TOLERANCE 3 confers enhanced resistance to abiotic stresses and increases grain yield in field.

Plants frequently suffer from environmental stresses in nature and have evolved sophisticated and efficient mechanisms to cope with the stresses. To balance between growth and stress response, plants are equipped with efficient means to switch off the activated stress responses when stresses diminish. We previously revealed such an off-switch mechanism conferred by Arabidopsis PARAQUAT TOLERANCE 3 (AtPQT3) encoding an E3 ubiquitin ligase, knockout of which significantly enhances resistance to abiotic stresses. To explore whether the rice homologue OsPQT3 is functionally conserved, we generated three knockout mutants with CRISPR-Cas9 technology. The OsPQT3 knockout mutants (ospqt3) display enhanced resistance to oxidative and salt stress with elevated expression of OsGPX1, OsAPX1 and OsSOD1. More importantly, the ospqt3 mutants show significantly enhanced agronomic performance with higher yield compared with the wild type under salt stress in greenhouse as well as in field conditions. We further showed that OsPQT3 expression rapidly decreased in response to oxidative and other abiotic stresses as AtPQT3 does. Taken together, these results show that OsPQT3 is functionally well conserved in rice as an off-switch in stress response as AtPQT3 in Arabidopsis. Therefore, PQT3 locus provides a promising candidate for crop improvement with enhanced stress resistance by gene editing technology.

Rice NIN-LIKE PROTEIN 1 rapidly responds to nitrogen deficiency and improves yield and nitrogen use efficiency.

Nitrogen (N) is indispensable for crop growth and yield, but excessive agricultural application of nitrogenous fertilizers has generated severe environmental problems. A desirable and economical solution to cope with these issues is to improve crop nitrogen use efficiency (NUE). Plant NUE has been a focal point of intensive research worldwide, yet much still has to be learned about its genetic determinants and regulation. Here, we show that rice (Oryza sativa L.) NIN-LIKE PROTEIN 1 (OsNLP1) plays a fundamental role in N utilization. OsNLP1 protein localizes in the nucleus and its transcript level is rapidly induced by N starvation. Overexpression of OsNLP1 improves plant growth, grain yield, and NUE under different N conditions, while knockout of OsNLP1 impairs grain yield and NUE under N-limiting conditions. OsNLP1 regulates nitrate and ammonium utilization by cooperatively orchestrating multiple N uptake and assimilation genes. Chromatin immunoprecipitation and yeast one-hybrid assays showed that OsNLP1 can directly bind to the promoter of these genes to activate their expression. Therefore, our results demonstrate that OsNLP1 is a key regulator of N utilization and represents a potential target for improving NUE and yield in rice.

An overview on pharmacological significance, phytochemical potential, traditional importance and conservation strategies of Dioscorea deltoidea: A high valued endangered medicinal plant.

Dioscorea deltoidea Wall. ex Griseb. is an endangered species of the Dioscoreaceae family. It is the most commonly consumed wild species as a vegetable due to its high protein, vital amino acid, vitamin, and mineral content. There are approximately 613 species in the genus Dioscorea Plum. ex L., which is found in temperate and tropical climates. Dioscorea deltoidea, a plant species widespread across tropical and sub-tropical regions, called by different names in different languages. In English, it is commonly referred to as "Wild yam" or "Elephant foot". The Sanskrit name for this plant is "Varahikand," while in Hindi, it is known as "Gun" or "Singly-mingly." The Urdu language refers to it as "Qanis," and in Nepali, it is called "Tarul," "Bhyakur," or "Ghunar." Dioscorea deltoidea has been used to cure a wide range of human ailments for centuries. This plant has nutritional and therapeutic uses and also contains high amounts of steroidal saponins, allantoin, polyphenols, and most notably, polysaccharides and diosgenin. These bioactive chemicals have shown potential in providing protection against a wide spectrum of inflammatory conditions, including enteritis (inflammation of the intestines), arthritis (joint inflammation), dermatitis (skin inflammation), acute pancreatitis (inflammation of the pancreas), and neuro inflammation (inflammation in the nervous system). Furthermore, the valuable bioactive chemicals found in D. deltoidea have been associated with a range of beneficial biological activities, such as antibacterial, antioxidant, anti-inflammatory, immunomodulatory, hepatoprotective, and cytotoxic properties. Sapogenin steroidal chemicals are highly valued in the fields of medicine, manufacturing, and commerce. It has both expectorant and sedative properties. It is employed in the treatment of cardiovascular diseases, encompassing various ailments related to the heart and blood vessels, skin disease, cancer, immune deficiencies, and autoimmune diseases. Additionally, it finds application in managing disorders of the central nervous system and dysfunctional changes in the female reproductive system. Furthermore, it is valued for its role in treating bone and joint diseases. Metabolic disorders are also among the ailments for which D. deltoidea is employed. It has traditionally been used as a vermifuge, fish poison, and to kill lice. Diosgenin, a steroidal compound found in D. deltoidea, plays a crucial role as a precursor in the chemical synthesis of various hormones. Due to the presence of valuable bioactive molecule, like corticosterone and sigmasterol, D. deltoidea is cultivated specifically for the extraction of these beneficial phytochemicals. The current study aims to assess D. deltoidea's medicinal properties, ethnobotanical usage, phytochemicals, pharmacological properties, threats, and conservation techniques.

Nitrate-responsive OsMADS27 promotes salt tolerance in rice.

Salt stress is a major constraint on plant growth and yield. Nitrogen (N) fertilizers are known to alleviate salt stress. However, the underlying molecular mechanisms remain unclear. Here, we show that nitrate-dependent salt tolerance is mediated by OsMADS27 in rice. The expression of OsMADS27 is specifically induced by nitrate. The salt-inducible expression of OsMADS27 is also nitrate dependent. OsMADS27 knockout mutants are more sensitive to salt stress than the wild type, whereas OsMADS27 overexpression lines are more tolerant. Transcriptomic analyses revealed that OsMADS27 upregulates the expression of a number of known stress-responsive genes as well as those involved in ion homeostasis and antioxidation. We demonstrate that OsMADS27 directly binds to the promoters of OsHKT1.1 and OsSPL7 to regulate their expression. Notably, OsMADS27-mediated salt tolerance is nitrate dependent and positively correlated with nitrate concentration. Our results reveal the role of nitrate-responsive OsMADS27 and its downstream target genes in salt tolerance, providing a molecular mechanism for the enhancement of salt tolerance by nitrogen fertilizers in rice. OsMADS27 overexpression increased grain yield under salt stress in the presence of sufficient nitrate, suggesting that OsMADS27 is a promising candidate for the improvement of salt tolerance in rice.

Clinical variables accompanying salt-sensitive essential hypertension in ethnic Kashmiri population.

BACKGROUND: Salt sensitivity is actually a measure of an individual's blood pressure response to salt intake. It has been reported that people who are salt sensitive have high prevalence of hypertension and target organ damage. The link between dietary salt intake and hypertension is well established, and a reduction in salt intake has been shown to lower blood pressure. SCOPE: In Kashmir, this achieves significance because of a high incidence of hypertension along with a high salt intake among ethnic Kashmiris. DESIGN AND METHODS: We analysed clinical variables accompanying salt sensitive hypertension among Kashmiri population in our on-going salt sensitivity study on 770 Kashmiri patients (250 men, 520 women) of age group 18years and above from March 2020 to June 2021. We studied the clinical variables accompanying salt sensitivity and the difference in their blood pressure on. a low salt diet (mean = 2 g/day) vs. their usual salt intake (mean = 11 g/day). To document compliance of salt-restricted diet, we used 24-h urinary NaCl estimation as a surrogate marker for salt intake estimation. RESULTS: We observed, a huge drop in SBP (-28.9 mmHg), DBP (-17.6 mmHg) and mean arterial pressure (-21.3mmHg) in this cohort of 770 ethnic Kashmiris on a strict salt restricted diet. And that women, urban inhabitants, and nonsmokers are more prone to the risk of developing salt sensitive hypertension. Physical activity had no effect on salt sensitivity. CONCLUSION: As per our study, salt restriction has a major role in treatment of Hypertension in Kashmiri Population. More studies need to be focused on this vital area.