Phospholipase A Activity during Cold Acclimation of Wheat (original) (raw)
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Crop Science, 2009
Nighttime temperature is one of the major environmental factors infl uencing plant metabolic processes. The respiration rates, membrane thermal stability (MTS), and total antioxidant capacities of leaves were investigated in rice (Oryza sativa L.) plants when exposed to high nighttime temperature (HNT) (32°C) or ambient nighttime temperature (ANT) (27°C), and with or without potential preventive exogenous effector (chemical) treatments. The exogenous effector treatments included α-tocopherol (vitamin E), glycine betaine, and salicylic acid, which play important but different roles in inducing thermal tolerance in many plant species. Plants were subjected to an HNT through use of continuously controlled infrared heaters, starting from 2000 h until 0600 h. High nighttime temperature increased respiration rates, decreased MTS, and negatively affected the yield (by 95%). Application of salicylic acid somewhat lowered the reduction in yield due to HNT (76 vs. 95%) by decreasing the respiration rates and increasing MTS and total antioxidant capacity of rice plants.
Plant, Cell & Environment, 2020
To further our understanding of how sustained changes in temperature affect the carbon economy of rice (Oryza sativa), hydroponically grown plants of the IR64 cultivar were developed at 30°C/25°C (day/night) before being shifted to 25/20°C or 40/35°C. Leaf messenger RNA and protein abundance, sugar and starch concentrations, and gas‐exchange and elongation rates were measured on preexisting leaves (PE) already developed at 30/25°C or leaves newly developed (ND) subsequent to temperature transfer. Following a shift in growth temperature, there was a transient adjustment in metabolic gene transcript abundance of PE leaves before homoeostasis was reached within 24 hr, aligning with Rdark (leaf dark respiratory CO2 release) and An (net CO2 assimilation) changes. With longer exposure, the central respiratory protein cytochrome c oxidase (COX) declined in abundance at 40/35°C. In contrast to Rdark, An was maintained across the three growth temperatures in ND leaves. Soluble sugars did not...
Phytochemistry, 2006
The effects of salicylic acid (SA) and cold on apoplastic protein levels and activities of apoplastic catalase (CAT), peroxidase (POX) and polyphenol oxidase (PPO) were investigated in winter wheat (Triticum aestivum cv. Dogu-88) leaves. The plants were grown with and without 10 lM SA treatment at both control (20/18°C for 30 and 45-day) and cold (10/5°C for 30-day and 5/3°C for 45-day) acclimatisations. Molecular masses of the apoplastic polypeptides were shown ranging in size from 20 to 66 kDa on SDS-PAGE. Accumulation and pattern of the polypeptides were changed by both SA and cold. It is observed that CAT, POX and PPO activities at 45-day control leaves were higher than at 30-day. When the activities with SA and cold treatments are compared to their controls, CAT activities were decreased while POX and PPO activities were increased by both the treatments. When the activities with cold + SA treatment are compared to their cold treatments, CAT and POX activities were decreased while PPO activity was increased by SA. It is concluded that exogenous SA can be involved in cold tolerance by regulating apoplastic proteins and antioxidant enzyme activities.
Antioxidative Enzymes Offer Protection from Chilling Damage in Rice Plants
Crop Science, 2003
the spring. This results in chilling injury to rice crops and sometimes to freezing injury due to spring frosts or Rice (Oryza sativa L.) is a tropical crop, but is also grown in occasional night freezing temperatures. Also, rice crops temperate regions in late spring to summer. Cold temperature damage is a common problem for early-planted rice in temperate countries.
Cold stress affects H + -ATPase and phospholipase D activity in Arabidopsis
Plant Physiology and Biochemistry, 2016
Low temperature is an environmental stress that greatly influences plant performance and distribution. Plants exposed to cold stress exhibit modifications of plasma membrane physical properties that can affect their functionality. Here it is reported the effect of low temperature exposure of Arabidopsis plants on the activity of phospholipase D and H þ-ATPase, the master enzyme located at the plasma membrane. The H þ-ATPase activity was differently affected, depending on the length of cold stress imposed. In particular, an exposure to 4 C for 6 h determined the strong inhibition of the H þ-ATPase activity, that correlates with a reduced association with the regulatory 14-3-3 proteins. A longer exposure first caused the full recovery of the enzymatic activity followed by a significant activation, in accordance with both the increased association with 14-3-3 proteins and induction of H þ-ATPase gene transcription. Different time lengths of cold stress treatment were also shown to strongly stimulate the phospholipase D activity and affect the phosphatidic acid levels of the plasma membranes. Our results suggest a functional correlation between the activity of phospholipase D and H þ-ATPase mediated by phosphatidic acid release during the cold stress response.
Rapid responses of plants to temperature changes
Temperature (Austin, Tex.), 2017
Temperature is one of the main environmental factors that affect plant metabolism. Considering that plants are sessile, their survival depends on the efficient activation of resistance responses to thermal stress. In this comprehensive review, we discuss recent work on rapid biochemical and physiological adjustments, herein referred to as those occurring during the first few hours or a few days after the beginning of the change in the ambient temperature. The short-term metabolic modulation after plant exposure to heat and cold, including chilling and freezing, is discussed. Effects on photosynthesis, cell membranes, antioxidant system, production of heat shock proteins and nitric oxide, as well as an overview of signaling events to heat or cold stress are presented. In addition, we also discuss the acclimation process that occurs when the plant acquires resistance to an increase or decrease in temperature, adjusting its homeostasis and steady-state physiology to the new temperature...
Cell Biochemistry and Biophysics, 2014
The cellular changes induced by cold stress (CS) include responses that lead to oxidative stress and limits plant growth, metabolism, and productivity. In this study, responses of physio-biochemical to CS phases were comparatively studied in three genotypes of bread and durum wheats differing in sensitivity, two of them (Norstar, bread wheat and Gerdish, durum wheat) were tolerant to CS and the other one, SRN (durum wheat) was sensitive to CS. 14-day-old seedlings were subjected to CS (12 and 24 h) with or without cold acclimation (CA) phase. During CS, the elevated levels of electrolyte leakage index, contents of hydrogen peroxide (H 2 O 2), and malondialdehyde in Norstar and Gerdish were lower than that of SRN plants. Positive correlation and coregulation of reactive oxygen species (ROS) scavenging systems, superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, and proline especially after CA phase suggested crucial role for holding back toxic ROS levels in CS phase. However, different activities of this system resulted in different intensities of oxidative stress in acclimated and non-acclimated plants. Our results showed that a CA phase induced oxidative stress tolerance by modulating antioxidative systems. These responses confirmed the existence of wide range of genetic capacity in durum wheat to increase cold tolerance particularly in Gerdish so that the sensitivity of SRN plants to CS was linearly correlated with the more decrease of antioxidant systems. These general responses may be a sign for associating other metabolites or enzymes activities to create partly tolerance against coldinduced oxidative stress. Eventually, assessing the dynamic of cell responses in short intervals after CS without CA phases profitably could be a novel path in plant stress response investigations in a short period of time.
To investigate the response of rice growth and photosynthesis to different nitrogen (N) sources under cold stress, hydroponic cultivation of rice was done in greenhouse, with glycine, ammonium, and nitrate as the sole N sources. The results demonstrate that exposure to low temperature reduced the rice biomass and leaf chlorophyll content, but their values in the glycine-treated plants were significantly higher than in the ammonium-and nitrate-treated plants. This might be attributed to the higher N uptake rate and root area and activity in the glycine-treated plants. The glycine-treated plants also maintained high contents of soluble proteins, soluble sugars, and proline as well as enhanced antioxidant enzyme activities to protect themselves against chilling injury. Under cold stress, reduced stomatal conductance (g s) and effective quantum efficiency of PSII (F PSII) significantly inhibited the leaf photo-synthesis; however, glycine treatment alleviated these effects compared to the ammonium and nitrate treatments. The high non-photochemical quenching (qN) and excess energy dissipative energy (E x) in the glycine-treated plants were beneficial for the release of extra energy, thereby, strengthening their photochemical efficiency. We, therefore, conclude that the strengthened cold tolerance of glycine-treated rice plants was closely associated with the higher accumulation of dry matter and photosynthesis through the up-regulation of N-uptake, and increase in the content of osmoprotectants, activities of the antioxidant defense enzymes, and photochemical efficiency. The results of the present study provide new ideas for improving the plant tolerance to extreme temperatures by nutrient resource management in the cold regions.
Cold-induced changes of enzymes, proline, carbohydrates, and chlorophyll in wheat
Russian Journal of Plant Physiology, 2010
Quantitative changes in total leaf soluble proteins, proline, carbohydrate content, chlorophyll fluorescence, guaiacol peroxidase (POD) and catalase (CAT) activities were determined in a less cold-hardy (LCH) spring cv. Kohdasht (LT50 = −6°C), a semi cold-hardy (SCH) facultative cv. Azar 2 (LT50 = −15°C), and a cold-hardy (CH) winter cv. Norstar (LT50 = −26°C) of wheat (Triticum aestivum L.) exposed to 4°C for 9 weeks. Seedlings were grown in a controlled growth room for 14 days at 20°C and then transferred to 4°C (experimental day 0) for 63 days (cold treatment); otherwise they were maintained continuously at 20°C (control treatment). The samples were harvested 0, 2, 21, 28, 42, and 63 days after exposure to 4°C. The results showed significant low temperature (LT)-induced accumulation of total soluble proteins, proline, and carbohydrates and elevation in activities of CAT and POD in leaves of SCH and CH winter cultivars rather than in LCH spring cultivar. In contrast, the chlorophyll fluorescence (F v/F m) declined during LT treatment irrespective of cultivar. The results suggest that developmental traits such as vernalization requirement of wheat affects on cold-tolerance expression system of plants.