Comprehensive analysis of physiological and metabolomic responses to drought reveals specific modulation of acquired tolerance mechanisms in rice.

Mild stresses induce "acquired tolerance traits" (ATTs) that provide tolerance when stress becomes severe. Here, we identified the genetic variability in ATTs among a panel of rice germplasm accessions and demonstrated their relevance in protecting growth and productivity under water-limited conditions. Diverse approaches, including physiological screens, association mapping and metabolomics, were adopted and revealed 43 significant marker-trait associations. Nontargeted metabolomic profiling of contrasting genotypes revealed 26 "tolerance-related-induced" primary and secondary metabolites in the tolerant genotypes (AC-39000 and AC-39020) compared to the susceptible one (BPT-5204) under water-limited condition. Metabolites that help maintain cellular functions, especially Calvin cycle processes, significantly accumulated more in tolerant genotypes, which resulted in superior photosynthetic capacity and hence water use efficiency. Upregulation of the glutathione cycle intermediates explains the ROS homeostasis among the tolerant genotypes, maintaining spikelet fertility, and grain yield under stress. Bioinformatic dissection of a major effect quantitative trait locus on chromosome 8 revealed genes controlling metabolic pathways leading to the production of osmolites and antioxidants, such as GABA and raffinose. The study also led to the identification of specific trait donor genotypes that can be effectively used in translational crop improvement activities.

Recent Advances in Agronomic and Physio-Molecular Approaches for Improving Nitrogen Use Efficiency in Crop Plants.

The efficiency with which plants use nutrients to create biomass and/or grain is determined by the interaction of environmental and plant intrinsic factors. The major macronutrients, especially nitrogen (N), limit plant growth and development (1.5-2% of dry biomass) and have a direct impact on global food supply, fertilizer demand, and concern with environmental health. In the present time, the global consumption of N fertilizer is nearly 120 MT (million tons), and the N efficiency ranges from 25 to 50% of applied N. The dynamic range of ideal internal N concentrations is extremely large, necessitating stringent management to ensure that its requirements are met across various categories of developmental and environmental situations. Furthermore, approximately 60 percent of arable land is mineral deficient and/or mineral toxic around the world. The use of chemical fertilizers adds to the cost of production for the farmers and also increases environmental pollution. Therefore, the present study focused on the advancement in fertilizer approaches, comprising the use of biochar, zeolite, and customized nano and bio-fertilizers which had shown to be effective in improving nitrogen use efficiency (NUE) with lower soil degradation. Consequently, adopting precision farming, crop modeling, and the use of remote sensing technologies such as chlorophyll meters, leaf color charts, etc. assist in reducing the application of N fertilizer. This study also discussed the role of crucial plant attributes such as root structure architecture in improving the uptake and transport of N efficiency. The crosstalk of N with other soil nutrients plays a crucial role in nutrient homeostasis, which is also discussed thoroughly in this analysis. At the end, this review highlights the more efficient and accurate molecular strategies and techniques such as N transporters, transgenes, and omics, which are opening up intriguing possibilities for the detailed investigation of the molecular components that contribute to nitrogen utilization efficiency, thus expanding our knowledge of plant nutrition for future global food security.

Why are people dying due to tuberculosis? A study from Alappuzha District, Kerala, India.

BACKGROUND: Tuberculosis (TB)is a major killer disease worldwide. It is the ninth leading cause of death worldwide and the leading cause from a single infectious agent. In India also, TB kills about 480,000 persons every year and more than 1400 every day. Vision of the National TB Control Programme is TB-Free India with zero deaths, disease and poverty due to TB. Specific targets set in the End TB strategy include a 90% reduction in TB deaths and an 80% reduction in TB incidence by 2030, compared with 2015. Understanding about real cause of death is important to plan strategies to further prevent TB deaths. In the above circumstances we conducted a study, the objective of which was to find out the cause of deaths among patients registered in RNTCP unit of Alappuzha district of Kerala, India. METHODS: In RNTCP a patient who died during the course of treatment regardless of cause is declared as 'Died' due to TB. During the year 2015, 1618 cases were registered in RNTCP of Alappuzha district of which 90 patients died, showing a case fatality rate of 5.56%. Verbal autopsy can be considered as an essential public health tool for studying reasonable estimate of the cause of death at a community level even though not an accurate method at individual level. As part of the study, we visited the 4 RNTCP units of the district and collected the address of the TB patients who died in the area. With the help of the field staff we visited their houses and filled the death audit form of RNTCP along with the additional details. Verbal autopsy was conducted using WHO verbal autopsy format 2012 with immediate house hold contacts. RESULTS: Out of 90 deaths which occurred, three addresses could not be traced and another 15 patient relatives could not be contacted as they migrated out or were not available at their homes on two visits. Among them, mean age was found to be 62.6 years (SD+12.9). Males were 67 (77%) and rest 20 (23%)were females. Cause of death was analysed after Verbal autopsy for 72 deaths. Among 72 deaths, it was found that 29 (40.3%) had nothing other than TB, where as cause of death for 13 (18.1%) patients was myocardial infarction, 11 (15.3%) had cancer, 2 (2.8%) stroke and 17 (23.7%) other causes which include bronchiectasis, COPD, chicken pox, hepatitis, renal failure, and suicide. Only in 35 cases nothing other than TB could be suggested as a cause of death. Thus in 52 out of 87 (60%) cases, the causes of death were diseases other than TB. CONCLUSION: Among the TB deaths in Alappuzha district, 60% of deaths were due to diseases other than TB. Along with early diagnosis of all TB cases, screening for co-morbidity, appropriate management of co-morbidity and periodic clinical review of TB patients should also be part of the major strategies to prevent TB related deaths.

Orbital Exenteration in Rhino-Orbito-Cerebral Mucormycosis: A Prospective Analytical Study with Scoring System.

Mucormycosis is an uncommon, rapidly progressive, angio-invasive, commonly fatal, opportunistic fungal infection. The most critical decision in the management of rhinoorbital mucormycosis is whether the orbit should be exenterated. (1) To layout the indications of orbital exenteration in patients with rhino-orbito-cerebral mucormycosis. (2) To devise a scoring system that predicts the stage at which the exenteration needs to be carried out. A scoring system was devised by a team of experienced Otorhinolaryngologists and Ophthalmologists from prior experience in managing mucormycosis. All patients of mucormycosis visiting our hospital were admitted and included in the study. A total of 15 patients were included. The scoring system is based on 3 main criteria, namely: (1) clinical signs and symptoms. (2) Direct and Indirect Ophthalmoscopy. (3) Imaging. The Sion Hospital Scoring System is an accurate and promising measure to solve the dilemma that is associated with orbital exenteration in orbito-rhino-cerebral mucormycosis.

Introgression of Root and Water Use Efficiency Traits Enhances Water Productivity: An Evidence for Physiological Breeding in Rice (Oryza sativa L.).

BACKGROUND: Semi-irrigated aerobic cultivation of rice has been suggested as a potential water saving agronomy. However, suitable cultivars are needed in order to sustain yield levels. An introgression of water mining and water use efficiency (WUE) traits is the most appropriate strategy for a comprehensive genetic enhancement to develop such rice cultivars. RESULTS: We report a novel strategy of phenotyping and marker-assisted backcross breeding to introgress water mining (root) and water use efficiency (WUE) traits into a popular high yielding cultivar, IR-64. Trait donor genotypes for root (AC-39020) and WUE (IET-16348) were crossed separately and the resultant F1s were inter-mated to generate double cross F1s (DCF1). Progenies of three generations of backcross followed by selfing were charatcerised for target phenotype and genome integration. A set of 260 trait introgressed lines were identified. Root weight and root length of TILs were 53% and 23.5% higher, while Δ13C was 2.85‰ lower indicating a significant increase in WUE over IR-64. Five best TILs selected from BC3F3 generation showed 52% and 63% increase in yield over IR-64 under 100% and 60% FC, respectively. The trait introgressed lines resembled IR64 with more than 97% of genome recovered with a significant yield advantage under semi-irrigated aerobic conditions The study validated markers identified earlier by association mapping. CONCLUSION: Introgression of root and WUE into IR64, resulted in an excellent yield advantage even when cultivated under semi-irrigated aerobic condition. The study provided a proof-of-concept that maintaining leaf turgor and carbon metabolism results in improved adaptation to water limited conditions and sustains productivity. A marker based multi-parent backcross breeding is an appropriate approach for trait introgression. The trait introgressed lines developed can be effectively used in future crop improvement programs as donor lines for both root and WUE.

Discovery and mapping of genomic regions governing economically important traits of Basmati rice.

BACKGROUND: Basmati rice, originated in the foothills of Himalayas, commands a premium price in the domestic and international markets on account of its unique quality traits. The complex genetic nature of unique traits of Basmati as well as tedious screening methodologies involved in quality testing have been serious constraints to breeding quality Basmati. In the present study, we made an attempt to identify the genomic regions governing unique traits of Basmati rice. RESULTS: A total of 34 Quantitative Trait Loci (QTLs) for 16 economically important traits of Basmati rice were identified employing F(2), F(3) and Recombinant Inbred Line (RIL) mapping populations derived from a cross between Basmati370 (traditional Basmati) and Jaya (semi-dwarf rice). Out of which, 12 QTLs contributing to more than 15 % phenotypic variance were identified and considered as major effect QTLs. Four major effect QTLs coincide with the already known genes viz., sd1, GS3, alk1 and fgr governing plant height, grain size, alkali spreading value and aroma, respectively. For the remaining major QTLs, candidate genes were predicted as auxin response factor for filled grains, soluble starch synthase 3 for chalkiness and VQ domain containing protein for grain breadth and grain weight QTLs, based on the presence of non-synonymous single nucleotide polymorphism (SNPs) that were identified by comparing Basmati genome sequence with that of Nipponbare. CONCLUSIONS: To the best of our knowledge, the current study is the first attempt ever made to carry out genome-wide mapping for the dissection of the genetic basis of economically important traits of Basmati rice. The promising QTLs controlling important traits in Basmati rice, identified in this study, can be used as candidates for future marker-assisted breeding.