Search Results

You are looking at 121 - 130 of 798 items for :

  • Refine by Access: User-accessible Content x
Clear All
Free access

Erick Amombo, Longxing Hu, Jibiao Fan, Zhengrong Hu, and Jinmin Fu

oxidative damage, lipid peroxidation, bp modifications and sugar fragmentation in nucleic acids, and eventually cell death ( Palmer and Paulson, 1997 ). Plants have evolved different enzymatic and nonenzymatic scavenging mechanisms for ROS regulation

Free access

Ao Liu, Jibiao Fan, Margaret Mukami Gitau, Liang Chen, and Jinmin Fu

according to Duncan’s multiple range tests. Membrane injury and lipid peroxidation. MDA and EL can be used as efficient indicators of lipid peroxidation, which further reflects the extent of damage of cell membrane ( Södergren et al., 2001 ; Whitlow et al

Free access

Lisa Tang, Shweta Chhajed, Tripti Vashisth, Mercy A. Olmstead, James W. Olmstead, and Thomas A. Colquhoun

burst (GO:0045730), oxygen and ROS metabolic process (GO:0006800), hydrogen peroxide metabolic process (GO:0042743), and lipid oxidation (GO:0034440) ( Table 2 ). In addition, a number of DEGs related to antioxidant activity were upregulated at 3 DAT

Free access

Hazel Y. Wetzstein and S. Edward Law

). Histochemical and biochemical analyses of the stigmatic exudate show that it is heterogeneous and composed of lipids, polysaccharides, and proteins. Cresti et al. (1982) evaluated the stigma of Citrus limon and using SEM evaluations of fresh tissues

Free access

Ningguang Dong, Jianxun Qi, Yuanfa Li, Yonghao Chen, and Yanbin Hao

and lipid peroxidation and significantly prevented the decreased F v / F m and survival induced by chilling stress ( Fig. 5A–D ). These observations were consistent with those of other studies in Trigonobalanus doichangensis ( Zheng et al., 2015

Free access

Stephen B. Ryu and Jiwan P. Palta

Lipids have been thought to be important largely in membrane structure and energy reserve. It is now evident that lipids and lipid-derived metabolites play a role in many critical cellular processes. Recent studies have shown that membrane lipid-based signaling mediated by phospholipases such as phospholipase A2 (PLA2), phospholipase C (PLC), and phospholipase D (PLD) constitutes a crucial step in plant responses to abiotic and biotic stresses. Phospholipases and their products also play a role during plant growth and development. For example, PLA2-derived lysophospholipids acted as growth regulators that retard senescence of plant tissues. Interestingly, the PLA2 products inhibited the activity of PLD, which has been suggested to be a key enzyme responsible for membrane lipid breakdown leading to plant senescence. Endogenous levels of lysophospholipids, such as lysophosphatidylethanolamine (LPE), could be increased in castor bean leaf discs by the treatment of auxin (50 μM), which is known to be a activator of PLA2. Pretreatment of leaf discs with a PLA2 inhibitor before auxin treatment nullified the auxin effect and rather resulted in accelerated senescence even compared to the nontreated control. Our recent results suggest a potential role of PLA2 products as biologically active molecules mediating hormonal regulation of growth and senescence. One such product LPE is being commercially exploited for retarding senescence and improving shelf life of fruits, vegetables, and cut flowers.

Free access

June Liu, Zhimin Yang, Weiling Li, Jingjin Yu, and Bingru Huang

nm, which was used to calculate chlorophyll content according to Arnon (1949) . Lipid peroxidation was measured based on malondialdehyde (MDA) content of leaves according to Dhindsa and Matowe (1981) with modifications. Fresh leaves (0.40 g fresh

Open access

Lisa O’Rear Knowles and J.A. Flore

Abstract

Periderm from the roots of carrot (Daucus carota L.) was isolated enzymatically and analyzed anatomically and chemically during development. The outer transverse walls of the phellem layer formed a continuous, external membrane containing chloroform/methanol-soluble lipids. Separated by thin layer chromatography, these lipids contained at least 6 major chemical groups, the most abundant of which cochromatographed with fatty acids. Scanning electron microscopy revealed the absence of surface fine structure. The periderm membrane decreased in weight with development of the root, attributable to reductions in both chloroform/methanol-soluble and insoluble material per unit area.

Open access

Zhou Li, Yan Peng, and Bingru Huang

H 2 O 2 can cause lipid peroxidation, proteins degradation, accelerated senescence, and even programmed cell death, whereas the lower level and rapidly alteration of H 2 O 2 acts as critical regulatory roles in intermediate signaling transduction

Free access

Shiow Y. Wang, Miklos Faust, and Michael J. Line

The effect of IAA on apical dominance in apple buds was examined in relation to changes in proton density (free water) and membrane lipid composition in lateral buds. Decapitation induced budbreak and enhanced lateral bud growth. IAA replaced apical control of lateral buds and maintained paradormancy. Maximal inhibition was obtained when IAA was applied immediately after the apical bud was removed; delaying application reduced the effect of IAA. An increase in proton density in lateral buds was observed 2 days after decapitation, whereas the change in membrane lipid composition occurred 4 days later. Removing the terminal bud increased membrane galacto- and phospholipids and the ratio of unsaturated to corresponding saturated fatty acids. Decapitation also decreased the ratio of free sterols to phospholipids in lateral buds. Applying thidiazuron to lateral buds of decapitated shoots enhanced these effects, whereas applying IAA to the terminal end of decapitated shoots inhibited the increase of proton density and prevented changes in membrane lipid composition in lateral buds. These results suggest that change in water movement alters membrane lipid composition and then induces lateral bud growth. IAA, presumably produced by the terminal bud, restricts the movement of water to lateral buds and inhibits their growth in apple.