Harnessing phytomicrobiome signals for phytopathogenic stress management.

Harnessing the phytomicrobiome offers a great opportunity to improve plant productivity and quality of food. In the recent past, several phytomicrobiome microbes have been explored for their potential involvement in increasing crop yield. This review strategically targets to harness the various dimensions of phytomicrobiome for biotic stress management of crop plants. The tripartite interaction involving plantmicrobiome-pathogen has been discussed. Positive interventions in this system so as to achieve disease tolerant plants has been forayed upon. The different signalling molecules sent out by interacting partners of phytomicrobiome have also been analysed. The novel concept of artificial microbial consortium in mitigation of pathogenic stress has also been touched upon. The aim of this review is to explore the hidden potential of phytomicrobiome diversity as a potent tool against phytopathogens, thereby improving crop health and productivity in a sustainable way.

StCaM2, a calcium binding protein, alleviates negative effects of salinity and drought stress in tobacco.

KEY MESSAGE: Overexpression of StCaM2 in tobacco promotes plant growth and confers increased salinity and drought tolerance by enhancing the photosynthetic efficiency, ROS scavenging, and recovery from membrane injury. Calmodulins (CaMs) are important Ca2+ sensors that interact with effector proteins and drive a network of signal transduction pathways involved in regulating the growth and developmental pattern of plants under stress. Herein, using in silico analysis, we identified 17 CaM isoforms (StCaM) in potato. Expression profiling revealed different temporal and spatial expression patterns of these genes, which were modulated under abiotic stress. Among the identified StCaM genes, StCaM2 was found to have the largest number of abiotic stress responsive promoter elements. In addition, StCaM2 was upregulated in response to some of the selected abiotic stress in potato tissues. Overexpression of StCaM2 in transgenic tobacco plants enhanced their tolerance to salinity and drought stress. Accumulation of reactive oxygen species was remarkably decreased in transgenic lines compared to that in wild type plants. Chlorophyll a fluorescence analysis suggested better performance of photosystem II in transgenic plants under stress compared to that in wild type plants. The increase in salinity stress tolerance in StCaM2-overexpressing plants was also associated with a favorable K+/Na+ ratio. The enhanced tolerance to abiotic stresses correlated with the increase in the activities of anti-oxidative enzymes in transgenic tobacco plants. Overall, our results suggest that StCaM2 can be a novel candidate for conferring salt and drought tolerance in plants.

Exploring the new dimensions of selenium research to understand the underlying mechanism of its uptake, translocation, and accumulation.

Selenium (Se) is a vital mineral for both plants and animals. It is widely distributed on the earth's crust and is taken up by the plants as selenite or selenate. Plants substantially vary in their physiological response to Se. The amount of Se in edible plants is genetically controlled. Its availability can be determined by measuring its phytoavailability in soil. The low concentration of Se in plants can help them in combating stress, whereas higher concentrations can be detrimental to plant health and in most cases it is toxic. Thus, solving the double-edged sword problem of nutritional Se deficiency and its elevated concentrations in environment requires a better understanding of Se uptake and metabolism in plants. The studies on Se uptake and metabolism can help in genetic biofortification of Se in plants and also assist in phytoremediation. Moreover, Se uptake and transport, especially biochemical pathways of assimilation and incorporation into proteins, offers striking mechanisms of toxicity and tolerance. These developments have led to a revival of Se research in higher plants with significant break throughs being made in the previous years. This review explores the new dimensions of Se research with major emphasis on key research events related to Se undertaken in last few years. Further, we also discussed future possibilities in Se research for crop improvement.

Genetic enhancement for semi-dwarf and bacterial blight resistance with enhanced grain quality characteristics in traditional Basmati rice through marker-assisted selection.

Ranbir Basmati is one of the traditional Basmati varieties of India and of the most popular traditional Basmati variety grown in Jammu's region (State of Jammu & Kashmir). It is a tall and short-duration variety with strong aroma and excellent cooking quality. However, it is susceptible to bacterial blight (BB) disease caused by Xanthomonas oryzae pv oryzae (Xoo) and prone to lodging. In this study, semi-dwarf (sd1) and BB resistance genes (Xa21 and xa13) were introgressed into Ranbir Basmati using marker-assisted backcross breeding (MABB) scheme. A high-yielding PAU148 carrying Xa21, xa13 and sd1 genes was used as a donor parent. On each generation target, genes were selected, while polymorphic SSR markers were used to select plants having maximum recovery of the recurrent genome. The maximum genome recovery of Ranbir Basmati in BC2F2 was 86.9% in introgressed line SBTIL121. The genotypes carrying resistant genes exhibited very high levels of tolerance against BB disease along with good Basmati rice grain quality traits. The agronomic traits of introgressed lines evaluated in the field and the laboratory showed that most of the agro-morphological traits were similar or superior to Ranbir Basmati. The identified lines can be further evaluated and released as Improved Ranbir Basmati variety.

Plant epigenetic mechanisms: role in abiotic stress and their generational heritability.

Plants have evolved various defense mechanisms including morphological adaptations, cellular pathways, specific signalling molecules and inherent immunity to endure various abiotic stresses during different growth stages. Most of the defense mechanisms are controlled by stress-responsive genes by transcribing and translating specific genes. However, certain modifications of DNA and chromatin along with small RNA-based mechanisms have also been reported to regulate the expression of stress-responsive genes and constitute another line of defense for plants in their struggle against stresses. More recently, studies have suggested that these modifications are heritable to the future generations as well, thereby indicating their possible role in the evolutionary mechanisms related to abiotic stresses.

Adolescents Living with HIV: An Indian Profile.

Purpose. Although there have been studies on the presence of Human Immunodeficiency Virus (HIV) among the adult and even pediatric population, the adolescent population has been neglected. The main objective of this study was to understand and describe the profile of adolescents accessing the Integrated Counseling and Testing Centre (ICTC) at a tertiary healthcare centre in north India. This was a retrospective analysis of the data collected where, in addition to the analysis of the presence of HIV among the target population, a comparative analysis of HIV-positive and negative individuals was also carried out. Methods. Counselors at the ICTC of All India Institute of Medical Sciences recorded responses of the patients, and pre- and posttest counseling was performed appropriately. Also, HIV testing was performed using rapid tests (EIA) and ELISA. Both pre- and posttest counseling was performed for most of the patients. Also, the data collected from 2005 to May, 2011 was then retrospectively analyzed using various statistical tests, such as, Chi-square test and odds ratios. Results. Out of 979, 84 tested HIV positive. Discrimination at multiple levels was observed.The 10-14 years age group was 0.56 times more likely to be HIV positive than 15-19 year old. HIV serostatus was strongly associated with risk behavior (P = 0.003) with heterosexual transmission being the most common. Conclusion. These findings highlight the profile of adolescents in India and their equation with HIV on demographic and psychosocial levels.

HIV voluntary counseling and testing: an experience from India.

Despite proof of voluntary counseling and testing (VCT) effectiveness in HIV disease prevention and management, there are limited reports on experience with pre- and post-HIV-test counseling in developing countries. In view of this, we aimed to bring to the fore the voluntary counseling and testing experience at a tertiary healthcare center. The present study was conducted at the voluntary counseling and testing center of a tertiary healthcare center and the National HIV Reference Center. Participants were 1169 men and 581 females attending the VCT clinic from February 2005 to March 2006. Odds ratios were calculated for each of the variable to analyze the strength of association with HIV sero-status. Out of 1750 patients, 322 (27.5%) males and 156 females (26.9%) tested HIV-positive. HIV-sero-positivity was observed to be associated to participant age (approximately 1.5 for 25-44 yrs age group), marital status (2.3 times in married patients), primary or lower education level (1.5 times), citing spouse death/HIV-infected spouse as the reason for seeking VCT (2.2 times) and reporting a history of risk behavior as reason for getting tested. This study aims to evaluate the effectiveness of existing client initiated voluntary counseling and testing facility in the light of a recent recommendation by WHO/UNAIDS for the implementation of provider initiated voluntary counseling services. Through this study, we could also highlight socio-demographic factors, like education and age, and reasons stated by participants for seeking VCT, which were associated with HIV-positive status and put an individual at a higher risk of HIV infection.