Showing papers by "Sarvajeet Singh Gill published in 2012"

Improving Growth and Productivity of Oleiferous Brassicas under Changing Environment: Significance of Nitrogen and Sulphur Nutrition, and Underlying Mechanisms

Abstract: Mineral nutrients are the integral part of the agricultural systems. Among important plant nutrients, nitrogen (N) and sulphur (S) are known essential elements for growth, development, and various physiological functions in plants. Oleiferous brassicas (rapeseed and mustard) require higher amounts of S in addition to N for optimum growth and yield. Therefore, balancing S-N fertilization, optimization of nutrient replenishment, minimization of nutrient losses to the environment, and the concept of coordination in action between S and N could be a significant strategy for improvement of growth and productivity of oleiferous brassicas. Additionally, positive interaction between S and N has been reported to be beneficial for various aspects of oilseed brassicas. The current paper updates readers on the significance of N and S for the improvement of plant growth, development, and productivity in detail. In addition, S-N nutrition-mediated control of major plant antioxidant defense system components involved in the removal and/or metabolism of stress-induced/generated reactive oxygen species in plants (hence, the control of plant growth, development, and productivity) has been overviewed.

Pea DNA helicase 45 promotes salinity stress tolerance in IR64 rice with improved yield

Abstract: The helicases provide duplex unwinding function in an ATP-dependent manner and thereby play important role in almost all the nucleic acids transaction Since stress reduces the protein synthesis by affecting the cellular gene expression machinery, so it is evident that molecules involved in nucleic acid processing including translation factors/helicases are likely to be affected Earlier pea DNA helicase 45 (PDH45), a homolog of translation initiation factor 4A (eIF4A) was reported to play important role in salinity stress tolerance in tobacco and Bangladeshi rice variety Binnatoa We report here the overexpression of PDH45 gene in the indica rice variety IR64, via Agrobacterium-mediated transformation Molecular analysis of the transgenics revealed stable integration of the transgene in the T1 generation Enhanced tolerance to salinity was observed in the plants transformed with PDH45 gene Better physiological and yield performances including endogenous nutrient contents (N, P, K, Na) of the transgenics under salt treatment were observed as compared with wild type (WT), vector control and antisense transgenics All these results indicated that the overexpression of PDH45 in the IR64 rice transgenics enable them to perform better with enhanced salinity stress tolerance and improved physiological traits Based on the homology of PDH45 protein with eIF4A protein we suggest that it may act at the translational level to enhance or stabilize protein synthesis under stress conditions

microRNAs as promising tools for improving stress tolerance in rice.

Abstract: Rice (Oryza sativa) represents one of the most important food crops in the world, since it feeds more than two billion people. The increased rice production can play significant roles in upgrading the economic status of countries like India and China. A great deal of research has been carried out in the recent past on the molecular biology, genomics and biotechnology of rice. By employing recombinant DNA technology, remarkable progress had been made towards production of rice plants with increase yield, improved nutritional quality and resistance to various diseases. Under these circumstances, the study of microRNAs can contribute to new discoveries in this field. The miRNAs are assign to modulate gene expression at the post-transcriptional level. They are small, non-coding, single stranded RNAs that are abundantly found in prokaryotic and eukaryotic cells and can trigger translational repression or gene silencing by binding to complementary sequences on target mRNA transcripts. In the recent years, miRNAs have been reported to control a variety of biological processes, such as plant development, differentiation, signal transduction or stress responses. The present review provides an up-date on microRNAs and their involvement in the stress response in rice. A section is specifically dedicated to the genetic engineering perspectives regarding the miRNAs applications in rice tolerance to stress conditions.

Piriformospora indica, A Root Endophytic Fungus, Enhances Abiotic Stress Tolerance of the Host Plant

Abstract: Manoj Kumar, Ruby Sharma, Abhimanyu Jogawat, Pratap Singh, Meenakshi Dua,Sarvajeet Singh Gill, Dipesh Kumar Trivedi, Narendra Tuteja, Ajit Kumar Verma, RalfOelmuller, and Atul Kumar JohriPiriformospora indica is an endophytic fungus that colonizes the roots of bothmonocot and dicot plants including members of the family Brassicaceae, which arenonhost for arbuscular mycorrhizal fungi (AMF) and can also be grown axenically.Like the AMF, P. indica was found to be involved in the enhancement of planttoleranceagainstabioticstress.Growthpromotioninplantisacharacteristiceffectofthe fungal colonization, which is visible under the stress conditions. P. indicamodulates the defense system and alters the metabolism to compensate the lossinphotosynthesisandpreventoxidativedamagecausedbystress.Primarily,P.indicainduces the defense system, especially the ascorbate–glutathione (ASH-GSH) cycle,and maintains a high antioxidative environment during salt and drought stress.P. indica also induces different antioxidative enzymes during salt and drought thatare involved in detoxification of reactive oxygen species (ROS) such as superoxidedismutase(SOD),catalase(CAT),ascorbateperoxidase(APX),glutathionereductase(GR), peroxidase (POD), monodehydroascorbate reductase (MDHAR), dehydroas-corbate reductase (DHAR), and so on. P. indica also increases the level of osmolytessuchaspolyamineandprolineinresponsetosalinityanddroughtstress.Interplayofantioxidative environment mediated by ASH, osmolytes (polyamine, proline, etc.),and antioxidative enzyme system leads to maintenance of plastid integrity andthereforeenhancedphotosyntheticefficiencyincolonizedplantduringabioticstress.In addition, P. indica also induces salt and drought stress-responsive genes, whichmay play an important role in increased abiotic stress tolerance of crop plants.24.1IntroductionThe unfavorable environmental parameters, such as drought, salinity, cold, freez-ing, high temperature, water logging, high light intensity, UV irradiation, nutrientimbalances, metal toxicities, nutrient deficiencies, climate change, and so on are

The Plant Family Brassicaceae: An Introduction

Abstract: This chapter introduces the plant family Brassicaceae (Cruciferae or mustard family) and also summarizes significant roles of some representative plant species from this family for metals and metalloids phytoremediation. Brassicaceae family is one of the largest dicot families of flowering (angiospermic) plant kingdom which comprises 10–19 tribes with a total of 338–360 genera and nearly 3,709 species. The Brassicaceae are easily recognized by having unique flowers [with four petals, forming a cross or sometimes reduced or lacking; six stamens, the outer two being shorter than the inner four (however, sometimes only two or four stamens are present) and capsule (having two valves capsule with a septum dividing it into two chambers)]. The plant family Brassicaceae includes several plant species of great scientific, economic and agronomic importance including model species (Arabidopsis and Brassica), developing model generic systems (Boechera, Brassica, and Cardamine), as well as many widely cultivated species. The well-known model plants from the family Brassicaceae viz., Arabidopsis (Arabidopsis thaliana) and Brassica species have revolutionized our knowledge in almost every field of modern plant biology. In addition, several representatives of the family Brassicaceae are equally playing significant roles for achieving environmental sustainability.

Metal Hyperaccumulation and Tolerance in Alyssum, Arabidopsis and Thlaspi: An Overview

Abstract: Toxic metals (TMs) and metalloids are natural components of environments, but elevated toxic levels and high persistence of TMs and metalloids in major compartments of the biosphere has posed various uncompromising and fatal effects on flora and fauna, and thus, has threatened the stability of the ecosystems as well. In addition, with the rapid increase in anthropological practices, a large number of TMs and metalloids ions are being added to the natural environment disrupting the ecosystem. A plethora of plant species have been identified so far to have potential for the remediation of TMs and metalloids-contaminated sites. Although, a large number of natural metal hyperaccumulator plant species from 34 different plant families including Asteraceace, Brassicaceae, Caryophyllaceae, Poaceae, Violaceae and Fabaceae has evolved the ability to take up, tolerate and accumulate exceptionally high concentrations of metals and metalloids present in the soil (and water) and, more importantly, in their aboveground biomass without visible toxicity symptoms but with 87 species classified as metal hyperaccumulators, the family Brassicaceae best represents amongst these metal-hyperaccumulator families. Of these 87 different metal-hyperaccumulator plant species in the family Brassicaceae, plant species in particular model metal hyperaccumutaor plant species Alyssum, Thlaspi and Arabidopsis have been studied extensively for their ability to hyperaccumulate, remove, destroy, degrade, sequester, transform, assimilate, metabolize or detoxify majority of TMs and metalloids in varied environmental compartments. Additionally, significant technological advancements in varied scientific fields have now deciphered important physiological and molecular mechanisms of TMs- and metalloids-remediation processes/intricacies in metal hyper accumulating plant species. Based on the plethora of recent published reports the current chapter critically discusses important strategies adopted by Alyssum, Arabidopsis and Thlaspi for TMs- and metalloids-hyperaccumulation/remediation and tolerance.

Polyamines in Developing Stress‐Resistant Crops

Abstract: F.Marco,R.Alcazar,T.Altabella,P.Carrasco,SarvajeetSinghGill,NarendraTuteja,andA.F. TiburcioPolyamines (PAs) are small protonated compounds with key roles in plant devel-opmentandphysiologicalprocesses.PAsmayalsofunctionasstressmessengersinplant responses to different stress signals. Recent studies using exogenous appli-cation of polyamines and more contemporary genetic manipulation of polyaminelevelsincropsandmodelspeciespointtotheirinvolvementinstressprotection.Thedifferentmechanismsbywhichpolyaminesexerttheirfunctionsarepresentlybeingunraveledandinvolvedifferentmodesofactionthataresummarizedinthischapter.Polyamines are integrated with other stress-related hormone pathways, such asabscisic acid (ABA), reactive oxygen species (ROS) signaling, nitric oxide, andregulation of ion channels that are now being elucidated. Also, polyamines areimplicated in the transcriptional regulation to abiotic and biotic stresses as revealedin recent global transcriptome analyses. The genetic manipulation of polyaminelevels has been proven tobe anefficient tool for enhancing stress tolerance in manyplant species. A number of examples and their potential application to crops for asustainable agriculture are discussed in this chapter, along with the most recentadvances in our understanding of the regulation and mode of action of polyamines.27.1Introduction27.1.1PA Biosynthesis and Catabolism in PlantsPlants live in an ever-changing and often unpredictable environment that repre-sents the major limiting factors for agricultural crop productivity. Plants, unlikeanimals, cannot move and therefore encounter a variety of environmental stressesthroughout their life cycle. It is predicted that the environmental stresses willbecome more intense and frequent with climate change, especially global warming.Among abiotic stresses, cold, heat, salinity, and drought adversely affect plantgrowthandproductivityandrestrictthecropstoreachtheirfullgeneticpotential[1].Q1