Firoz Mohammad

A review of ascorbic acid potentialities against oxidative stress induced in plants

A review of ascorbic acid potentialities against oxidative stress induced in plants Ascorbic acid (AA) currently holds a significant position in plant physiology, mainly due to its possession of antioxidant and cellular reductant etc.properties and its diverse roles in plant growth and development and the regulation of a broad spectrum of plant cellular mechanisms against environmental stresses. Some researchers suggest that endogenous AA has been implicated in the promotion of plant growth and development by involvement in a complex and enigmatic array of phytohormone-regulated signalling networks that ties together different environmental stresses. As it is evident from the present review, recent progress on AA potentiality in the tolerance of plants to environmental stresses has been impressive. Indeed, AA plays an important role in resistance to oxidative stresses such as heavy metal, saline, ultra-violet etc. Rapidly increasing evidence indicates that AA is centrally involved in several physiological processes but there has been much disagreement regarding the mechanism(s) by which AA reduces the damaging effects of such stresses in plants. Perhaps the role of AA in mediating tolerance to abiotic stress (e.g. UV, salinity and temperature, etc.) will lead to a greater research focus in the near future. In addition, AA might provide a suitably attractive target for the enhancement of crop production.

Morphological and physio-biochemical characterization of Brassica juncea L. Czern. & Coss. genotypes under salt stress

Abstract Soil salinity is one of the major factors responsible for the low productivity of crop plants and has become an increasing threat for agriculture. In this context, the selection of tolerant genotype/s may be one of the remedies. Keeping this in view, the effect of NaCl (0–120 mM) stress on shoot length (SL) plant−1, area (A) leaf−1, leaf area index (LAI), fresh weight (FW) and dry weight (DW) plant−1, stomatal conductance (gs), net photosynthetic rate (P N), total chlorophyll (Chl) content, malondialdehyde (MDA) content, sensitivity rate index (SRI), leaf- nitrogen (N), potassium (K) and sodium (Na) content, leaf-K/Na ratio, nitrate reductase (NR: EC.1.6.6.1) and ATP-sulphurylase (ATP-S: EC.2.7.7.4) activities and proline (Pro) and glycinebetaine (GB) content of ten genotypes of Brassica juncea L. was studied at 55 and 65 days after sowing (DAS). NaCl treatments decreased all the above parameters, except Pro, GB, MDA, Na and SRI at both stages. Salt stress resulted in accumulation of Pro and GB, in all genotypes. The magnitude of increase in both osmolytes (Pro and GB) was higher in genotype G8 than the other genotypes. Salt stress increased MDA and Na content while it decreased Chl, N and K content and K/Na ratio, Chl content, NR and ATP-S activities in all genotypes. But the magnitude of increase in MDA and Na content and decrease in SL plant−1, A leaf−1, LAI, P N, gs, Chl content and NR and ATP-S activities in genotype G8 was more than that of other genotypes. These results suggest that the salt-tolerant genotype may have better osmotic adjustment and protection from free radicals by increasing the accumulation of Pro and GB content with overproduction of N and K and higher K/Na, NR and ATP-S activities under salinity stress.

Nitrogen in relation to photosynthetic capacity and accumulation of osmoprotectant and nutrients in Brassica genotypes grown under salt stress.

Abstract Different strategies of the application of nutrients are required to overcome the adverse effects of mustard ( Brassica juncea L.) in response to NaCl stress. The objective of the present study was to determine if different added levels of nitrogen (N) in growth medium could alleviate the adverse effects of salt stress on photosynthetic capacity and accumulation of osmoprotectants and nutrients. 14 days mustard seedlings of salt-sensitive ( cv . Chuutki) and salt-tolerant ( cv. Radha) genotypes were fed with: (i) 0 mmol L −1 NaCl + 0 mg N kg −1 sand (control), (ii) 90 mmol L −1 NaCl + 30 mg N kg −1 sand, (iii) 90 mmol L −1 NaCl + 60 mg N kg −1 sand, (iv) 90 mmol L −1 NaCl + 90 mg N kg −1 sand and (v) 90 mmol L −1 NaCl + 120 mg N kg −1 sand. Under the condition of salinity stress, N application caused a significant ameliorative effect on both genotypes with respect to growth attributes [fresh weight (FW) and dry weight (DW)] and physio-biochemical parameters [percent water content (WC), net photosynthetic rate (P N ), stomatal conductance (g s ), total chlorophyll (Chl), carbonic anhydrase (CA) activity and malondialdehyde (MDA), nitrogen (N), potassium (K) and sodium (Na) contents, and K/Na ratio] and yield attributes (number of pods/plant, seeds/pod and seed yield/plant). The salt-tolerant genotype exhibited maximum value for growth, physio-biochemical and yield attributes at 60 mg N kg −1 sand than that of salt-sensitive genotype. These results suggest that application of N may ameliorate most of the attributes and prove to be a physiological remedy to increase the tolerance against the ill effects of salt stress in Brassicas .

Eutrophication: Challenges and Solutions

On the hydrological map of the world eutrophication has become the primary water quality issue. The excessive enrichment of waters with anthropogenic sources of nutrients especially nitrogen (N) and phosphorus (P) lead to the transformation of oligotrophic water bodies to mesotrophic, eutrophic, and finally hypertrophic. Mesotrophic and eutrophic phases exhibit intermediate and rich levels of nutrients and show increasing and serious water quality problems, respectively. Eutrophication restricts water use for fisheries, recreation, industry, and drinking because of increased growth of undesirable algae and aquatic weeds and the oxygen shortages caused by their death and decomposition. Associated periodic surface blooms of cyanobacteria (blue-green algae) occur in drinking water supplies and may pose a serious health hazard to animals and humans. Anthropogenic activities are the worst culprit of nutrient enrichment and root cause of eutrophication of water bodies. Excess nutrient inputs to water bodies usually come from sewage, industrial discharges, agricultural runoff, construction sites, and urban areas. Eutrophication can be minimized by regulating the nutrient sources, reducing the use of fertilizers, proper soil management practices, implementing mathematical models, phytoremediation etc. Among these, public awareness of eutrophication can play an important role in preventing the eutrophication of water bodies.

Cumulative Effect of Soil and Foliar Application of Nitrogen, Phosphorus, and Sulfur on Growth, Physico-Biochemical Parameters, Yield Attributes, and Fatty Acid Composition in Oil of Erucic Acid-Free Rapeseed-Mustard Genotypes

ABSTRACT The feasibility of split (soil + foliar) applications of nitrogen (N) and phosphorus (P) and addition of a small quantity of sulfur (S) in the spray was tested for improving performance of rapeseed-mustard genotypes in a factorial randomized field experiment. Three genotypes (two erucic acid free, viz. Brassica napus L. cv. ‘Hyola PAC – 401’ and Brassica juncea L. Czern. and Coss. cv. ‘TERI (0E) M 21-Swarna’, and one best performing high yielding Brassica juncea L. cv. ‘Rohini’ as a check) were grown with four soil (B) plus foliar (F) applications of N, P, and S with uniform basal 30 kg potassium (K) ha− 1 (K30), viz. (i) the optimum soil-applied treatment supplemented with the spray of deionized water (BN90P30 + Fw) comprising control, (ii) BN70P30 + F N20, (iii) BN70P28 + FN20P2, and (iv) BN70P28 + FN20P2S2. Soil Plus foliar application of nutrients, particularly BN70P28 + FN20P2S2, improved their performance with respect to growth characteristics (shoot length plant− 1, leaf number plant− 1, area leaf− 1, leaf area index, fresh weight plant− 1, and dry weight plant− 1), physico-biochemical parameters (net photosynthetic rate, stomatal conductance, carboxylation efficiency, water use efficiency, carbonic anhydrase activity, leaf NPK content, and N use efficiency), yield attributes (pod number plant− 1, seed number pod− 1, 1000-seed weight, seed yield ha− 1, oil content, and oil yield ha− 1), and fatty acid composition in oil of these genotypes. The cultivar ‘Hyola PAC-401’ performed best particularly with BN70P28 + FN20P2S2. The improvement in the response of genotypes to the split application of nutrients may be attributed to their ready availability through foliar application.

Gibberellic acid and triacontanol can ameliorate the opium yield and morphine production in opium poppy (Papaver somniferum L.)

Abstract A pot experiment was conducted during 2004–2005 on opium poppy (Papaver somniferum L.) and the influence of 10−6 M gibberellic acid (GA3) and 10−6 M triacontanol (TRIA) either alone or together, on the growth, yield, quality and morphine content. Among the treatments, foliar spray of GA3+TRIA significantly promoted the values of most of the physiological and biochemical parameters including the opium yield. The morphine content was also enhanced. The effects of GA3 and TRIA were similar when given individually, in general, while only TRIA induced branching in the plants. Another important finding of this experiment was that GA3+TRIA favoured the branching as well as the development of capsules at the same levels of height in all the branches. This influence will bring about a practical benefit by facilitating easier manual or mechanical lancing of the capsules, the collection of the latex and the harvesting of the opium poppies. Thus, we conclude that 10−6 M each of GA3 and TRIA given together may be used for maximizing the yield of opium and morphine.

EFFECT OF NITROGEN ON CARBONIC ANHYDRASE ACTIVITY, STOMATAL CONDUCTANCE, NET PHOTOSYNTHETIC RATE AND YIELD OF MUSTARD

Mustard (Brassica juncea L.) cv. Rohini was grown under three levels of urea nitrogen fertilization [0, 2, and 4 g(N) pot-1]. Carbonic anhydrase activity and net photosynthetic rate in leaves of 50 d-old plants as well as yield attributes at harvest increased with increasing levels of nitrogen. Stomatal conductance was not affected, and oil content decreased.

Effect of K application on leaf carbonic anhydrase and nitrate reductase activities, photosynthetic characteristics, NPK and NO3 contents, growth, and yield of mustard

In a sand culture experiment on mustard (Brassica juncea L. Czern. & Coss) cv. Varuna, all tested characteristics at 60 d stage and yield characteristics at harvest were enhanced by K application as its levels increased from 5 to 10, 15, 20, 25, and 30 mM K, with 20 mM K proving best.

Nitric oxide in plants : metabolism and role in stress physiology

Part I Nitric oxide: Metabolism, Identification and Detection 1 An Update to the Understanding of Nitric Oxide Metabolism in Plants Andrea Galatro and Susana Puntarulo 2 Biosynthesis of Nitric Oxide in Plants Tamas Roszer 3 Function of Peroxisomes as a Cellular Source of Nitric Oxide and Other Reactive Nitrogen Species Luis A. del Rio, Francisco J. Corpas, Juan B. Barroso, Eduardo Lopez-Huertas and Jose M. Palma 4 Role of Plant Mitochondria in Nitric Oxide Homeostasis During Oxygen Deficiency Halley Caixeta Oliveira and Ione Salgado 5 Production of Nitric Oxide by Marine Unicellular Red Tide Phytoplankton, Chattonella marina Daekyung Kim and Tatsuya Oda 6 Identification of Nitrosylated Proteins (SNO) and Applications in Plants Jean-Benoit Peltier, Abasse Fares and Michel Rossignol 7 Nitric Oxide: Detection Methods and Possible Roles during Jasmonate-regulated Stress Reponse Palmiro Poltronieri, Marco Taurino, Stefania Bonsegna, Stefania De Domenico and Angelo Santino 8 S-Nitrosoglutathionereductase: Key Regulator of Plant Development and Stress Response Mounira Chaki and Christian Lindermayr 9 Nitro-Fatty Acids: Synthesis, Properties and Role in Biological System Homero Rubbo and Andres Trostchansky Part II Nitric Oxide: Properties, Mode of Action and Functional Role in Stress Physiology 10 Nitric Oxide and Reactive Nitrogen Species Magdalena Arasimowicz-Jelonek, Jolanta Floryszak-Wieczorek, Dariusz Abramowski, and Karolina Izbianska 11 Nitric Oxide and Other Signaling Molecules: A Cross Talk in Response to Abiotic Stress Wei-Biao Liao and Ji-Hua Yu 12 Cytoprotective Role of Nitric Oxide under Oxidative Stress Y.S. Bakakina, E.V. Kolesneva, L.V. Dubovskaya and I.D. Volotovski 13 Phytohormones and Nitric Oxide Interactions During Abiotic Stress Responses Paulo T. Mioto, Luciano Freschi and Helenice Mercier 14 Tolerance of Plants to Abiotic Stress: A Role of Nitric Oxide and Calcium M. Nasir Khan, Firoz Mohammad, M. Mobin and M. Ali Saqib 15 Abiotic Stress Tolerance in Plants: Exploring the Role of Nitric Oxide and Humic Substances V. Mora, M. Olaetxea, E. Bacaicoa, R. Baigorri, M. Fuentes, A.M. Zamarreno and J.M. Garcia-Mina 16 Nitric Oxide in Relation to Plant Signaling and Defense Responses Mui-Yun Wong, Mansour Salati and Yee-Min Kwan 17 The Role of Nitric Oxide in Programmed Cell Death in Higher Plants Hu-Yi He, Ming-Hua Gu and Long-Fei He

Tolerance of Plants to Abiotic Stress: A Role of Nitric Oxide and Calcium

Plants are continuously exposed to changing environmental conditions such as temperature, drought, salinity, heavy metals, etc., which in their extreme limits pose serious threats and set the plants with impaired growth, physiological and biochemical activities that are witnessed by the losses in crop growth and yield. However, to cope with inimical stresses plants are equipped with a series of defense system that help them to perform normally even under stressful conditions. In order to activate the defense system, signaling networks in plants trigger the molecular machinery against that particular stress condition. Calcium (Ca2+) has been proven as one of the important second messengers in eliciting responses to diverse biotic and abiotic stress signals. These stress signals elevate the cytosolic Ca2+ concentration which is sensed by Ca2+-binding proteins such as calmodulin, calcium-dependent protein kinases, and calcineurin B-like proteins that initiate downstream events leading to changes in gene expression and plant adaptation to stress tolerance. Nitric oxide (NO) is a molecule with multifaceted roles in plant growth, development, and in the tolerance of plants to biotic and abiotic stresses. Besides, NO is involved in the elevation of cytosolic Ca2+ in response to biotic and abiotic stresses. Elevated level of Ca2+ concentration not only elicits specific physiological responses to a given signal but also serve to elevate and/or maintain NO generation. The present chapter is focused on the synergistic role of NO and calcium in eliciting responses to abiotic stress signals.