Exogenously applied nicotinic acid alleviates drought stress by enhancing morpho-physiological traits and antioxidant defense mechanisms in wheat.

Across the globe, the frequent occurrence of drought spells has significantly undermined the sustainability of modern high-input farming systems, particularly those focused on staple crops like wheat. To ameliorate the deleterious impacts of drought through a biologically viable and eco-friendly approach, a study was designed to explore the effect of nicotinic acid on different metabolic, and biochemical processes, growth and yield of wheat under optimal moisture and drought stress (DS). The current study was comprised of different levels of nicotinic acid applied as foliar spray (0 g L-1, 0.7368, 1.477, 2.2159 g L-1) and fertigation (0.4924, 0.9848, and 1.4773 g L-1) under normal conditions and imposed drought by withholding water at anthesis stage. The response variables were morphological traits such as roots and shoots characteristics, yield attributes, grain and biological yields along with biosynthesis of antioxidants. The results revealed that nicotinic acid dose of 2.2159 g L-1 out-performed rest of treatments under both normal and DS. The same treatment resulted in the maximum root growth (length, fresh and dry weights, surface area, diameter) and shoot traits (length, fresh and dry weights) growth. Additionally, foliar applied nicotinic acid (2.2159 g L-1) also produced as the highest spike length, grains spike-1, spikelet's spike-1 and weight of 1000 grains. Moreover, these better yield attributes led to significantly higher grain yield and biological productivity of wheat. Likewise in terms of physiological growth of wheat under DS, the same treatment remained superior by recording the highest SPAD value, relative water content, water potential of leaves, leaf area, stomatal conductance (292 mmolm-2S-1), internal carbon dioxide concentration, photosynthesis and transpiration rate. Interestingly, exogenously applied nicotinic acid remained effective in triggering the antioxidant system of wheat by recording significantly higher catalase, peroxidase, superoxide dismutase and ascorbate peroxidase.

Physiological insights into sulfate and selenium interaction to improve drought tolerance in mung bean.

The present study involved two pot experiments to investigate the response of mung bean to the individual or combined SO4 2- and selenate application under drought stress. A marked increment in biomass and NPK accumulation was recorded in mung bean seedlings fertilized with various SO4 2- sources, except for CuSO4. Compared to other SO4 2- fertilizers, ZnSO4 application resulted in the highest increase in growth attributes and shoot nutrient content. Further, the combined S and Se application (S + Se) significantly enhanced relative water content (16%), SPAD value (72%), photosynthetic rate (80%) and activities of catalase (79%), guaiacol peroxidase (53%) and superoxide dismutase (58%) in the leaves of water-stressed mung bean plants. Consequently, the grain yield of mung bean was markedly increased by 105% under water stress conditions. Furthermore, S + Se application considerably increased the concentrations of P (47%), K (75%), S (80%), Zn (160%), and Fe (15%) in mung bean seeds under drought stress conditions. These findings indicate that S + Se application potentially increases the nutritional quality of grain legumes by stimulating photosynthetic apparatus and antioxidative machinery under water deficit conditions. Our results could provide the basis for further experiments on cross-talk between S and Se regulatory pathways to improve the nutritional quality of food crops. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-00992-6.

Understanding brassinosteroid-regulated mechanisms to improve stress tolerance in plants: a critical review.

Brassinosteroids (BRs) are steroidal plant hormones involved in regulation of physiological and molecular processes to ameliorate various biotic and abiotic stresses. Exogenous application of BRs to improve stress tolerance in plants has recently become a high research priority. Several studies have revealed the involvement of these steroidal hormones in upregulation of stress-related defense genes and their cross talk with other metabolic pathways. This is likely to stimulate research on many unanswered questions regarding their role in enhancing the ability of plants to tolerate adverse environmental conditions. Thus, this review appraises new insights on mechanisms mediating BR-regulated changes in plants, focused mainly on their involvement in regulation of physiological and molecular mechanisms under stress conditions. Herein, examples of BR-stimulated modulation of antioxidant defense system and upregulation of transcription factors in plants exposed to various biotic (bacterial, viral, and fungal attack) and abiotic stresses (drought, salinity, heat, low temperature, and heavy metal stress) are discussed. Based on these insights, future research in the current direction can be helpful to increase our understanding of BR-mediated complex and interrelated processes under stress conditions.

Frequency of Hepatic Hydrothorax and its Association with Child Pugh Class in Liver Cirrhosis Patients.

OBJECTIVE: To determine the frequency of hepatic hydrothorax and its association with Child Pugh Class in patients with liver cirrhosis. STUDY DESIGN: Descriptive, analytical study. PLACE AND DURATION OF STUDY: Jinnah Postgraduate Medical Centre, Karachi, Medical Unit-III, (Ward- 7), from June 2012 to May 2013. METHODOLOGY: All patients with established diagnosis of decompensated chronic liver disease were included. Detailed history, thorough physical examination, routine laboratory investigations, chest X-ray and abdominal ultrasound were carried out in all patients to find out the presence of pleural effusion and ascites, respectively. Fifty milliliters of pleural fluid was aspirated in all patients with pleural effusion using the transthoracic approach, taking ultrasound guidance, wherever required. Fluid was sent for microscopic, biochemical, and microbial analysis. SBEM defined if pleural fluid with polymorphonuclear (PMN) cell count > 500 cells/mm3 or positive culture with PMN cell count > 250 cells/mm3 with exclusion of a parapneumonic effusion. RESULTS: Two hundred and six patients met the inclusion criteria, with mean age of 41.25 ±13.59 years. Among them, 149 (72.3%) were males and 57 (27.7%) females. Twenty-three (11.2%) had hydrothorax; right sided involvement was in 18 (78.3%) subjects, 3 (13%) had left sided while bilateral pleural effusion was found in 2 (8.7%) cases. SBEM was found in 07 (30.43%) cases. Mean serum albumin 3.125 ±0.71 gram/dl. There was association between serum albumin levels and hydrothorax. Asignificant association of hydrothorax with Child Pugh scoring system (p=0.018), but not with serum albumin (p=0.15). CONCLUSION: The frequency of hepatic hydrothorax has a significant association with hepatic function as assessed by Child Pugh scoring system, but not with serum albumin.