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Kondratovičs T, Zeps M, Rupeika D, Zeltiņš P, Gailis A, Matisons R. Morphological and Physiological Responses of Hybrid Aspen ( Populus tremuloides Michx. × Populus tremula L.) Clones to Light In Vitro. PLANTS (BASEL, SWITZERLAND) 2022; 11:2692. [PMID: 36297714 PMCID: PMC9607416 DOI: 10.3390/plants11202692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/04/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Micropropagation of fast-growing tree genotypes such as the hybrid aspen (Populus tremuloides Michx. × Populus tremula L.) is increasing. The efficiency of micropropagation depends on the luminaires, hence luminescent electric diodes (LED), which emit light of a narrow spectrum, are gaining popularity. Mostly, different LEDs are combined to increase the photosynthetic efficiency. However, light also acts as an environmental signal, which triggers specific responses in plants, which are genotype specific, and regarding hybrid aspen, are likely affected by heterosis. In this study, morphological and physiological responses of clones of hybrid aspen with contrasting field performance to the spectral composition of illumination were studied in vitro. Among the 15 variables measured, area of leaves and concentration and ratio of chlorophyll a and b explained most of the variance (58.6%), thereby linking a specific combination of traits to productivity. These traits and their responses to light were affected by heterosis, as indicated by the clone-treatment interaction, particularly for the clone's moderate productivity. The top-performing clones were little sensitive to illumination due to efficient photosystems. Nevertheless, illumination with wider spectral composition had generally positive effects on plantlet performance. Accordingly, clone-specific illumination protocols and luminaries capable of it are advantageous for the efficiency of micropropagation of hybrid aspen.
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Wang L, Qin Z, Li X, Yang J, Xin M. Persistence behavior of chlorpyrifos and biological toxicity mechanism to cucumbers under greenhouse conditions. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 242:113894. [PMID: 35872489 DOI: 10.1016/j.ecoenv.2022.113894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/13/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Chlorpyrifos, a broadly utilized insecticide, inhibits many cellular and physiological processes in plants. Here, the phyto-toxicity of chlorpyrifos on cucumber plants, as well as the dissipation kinetics of chlorpyrifos in leaves, were investigated. Those results showed that chlorpyrifos accumulated primarily in the leaves under normal agrochemical spraying conditions with the half-lives among 2.48-4.59 days. Residues of the primary metabolite, 3,5,6-trichloro-2-pyridinol (TCP), rapidly accumulated in plant tissues and soil with chlorpyrifos degradation. The application amount of chlorpyrifos had a significant effect on the persistence of chlorpyrifos and TCP in both plant and soil environments. Chlorpyrifos generated excessive reactive oxygen species (ROS) and malondialdehyde (MDA), which led to oxidative damage. High chlorpyrifos stress even inhibited antioxidant enzymes. The photosynthetic system and gas exchange were suppressed, which ultimately lead to inefficient light use under chlorpyrifos stress. Morphological results revealed that chlorpyrifos induced membrane damage and harmed organelles such as mitochondria and chloroplast. Noninvasive micro-test technology (NMT) showed that chlorpyrifos promoted intracellular Ca2+ influx and efflux of H+ and K+. The Ca2+ influx was significantly stimulated after both high and low chlorpyrifos treatment with the minimum value of - 336.33 pmol·cm-2·s-1 at 258 s and - 155.68 pmol·cm-2·s-1 at 288 s, respectively. Chlorpyrifos stress reversed the H+ influx to an efflux in cucumber mesophyll with the mean value of 0.45 ± 0.03 pmol·cm-2·s-1 and 0.19 ± 0.03 pmol·cm-2·s-1 in cucumber plants under low and high chlorpyrifos stress. High chlorpyrifos stress dramatically increase K+ efflux in cucumber leaves by 13.68 times higher than the control. We suggest that ion homeostasis destruction, accompanied by ROS, resulted in oxidative damage to the mesophyll cell of cucumber seedlings.
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Affiliation(s)
- Lei Wang
- School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China
| | - Zhiwei Qin
- College of Horticulture and Landscape Architecture, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Northeast Agricultural University, Harbin, PR China
| | - Xiaoyue Li
- College of Horticulture and Landscape Architecture, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Northeast Agricultural University, Harbin, PR China; School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China
| | - Jing Yang
- College of Horticulture and Landscape Architecture, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Northeast Agricultural University, Harbin, PR China
| | - Ming Xin
- College of Horticulture and Landscape Architecture, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northeast Region), Northeast Agricultural University, Harbin, PR China.
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Liang C, Zhang Y, Ren X. Calcium regulates antioxidative isozyme activity for enhancing rice adaption to acid rain stress. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 306:110876. [PMID: 33775371 DOI: 10.1016/j.plantsci.2021.110876] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 02/05/2021] [Accepted: 03/06/2021] [Indexed: 05/08/2023]
Abstract
Acid rain, as a typical abiotic stress, damages plant growth and production. Calcium (Ca) mediates plant growth and links the signal transduction in plants for adapting to abiotic stresses. To understand the effect of Ca2+ on plant adaptable response to acid rain, we investigated changes in activities and gene expression of antioxidative enzymes and fatty acid composition of membrane lipid in rice seedlings treated with exogenous Ca2+ (5 mM) or/and simulated acid rain (SAR, pH 3.5 / 2.5). Exogenous Ca2+ enhanced activities of superoxide dismutase, catalase and peroxidase isozymes in rice leaves under SAR stress by promoting activation of existing isoforms and up-regulation of Cu/Zn-SOD1, Cu/Zn-SOD2, Cu/Zn-SOD3, CAT1, CAT2 and POD1. Compared to SAR treatment alone, exogenous Ca2+ alleviated SAR-induced oxidative damage to cell membrane by enhancing antioxidative capacity, as shown by the decrease in concentrations of H2O2, O2- and malondialdehyde in rice leaves. Meanwhile, Ca2+ alleviated SAR-induced decrease in unsaturation of membrane lipid for maintaining membrane fluidity. Finally, exogenous Ca2+ alleviated SAR-induced inhibition on relative growth rate of rice. Therefore, Ca2+ could play a role in regulating activities of antioxidative enzymes as well as maintaining unsaturation of membrane lipid for enhancing tolerance in rice seedlings to acid rain stress.
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Affiliation(s)
- Chanjuan Liang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, Wuxi, 214122, China; Jiangsu Cooperative Innovation Center of Technology and Material of Water Treatment, China.
| | - Yuanqi Zhang
- Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Xiaoqian Ren
- Jiangsu Cooperative Innovation Center of Technology and Material of Water Treatment, China
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Majumdar A, Kar RK. Chloroplast avoidance movement: a novel paradigm of ROS signalling. PHOTOSYNTHESIS RESEARCH 2020; 144:109-121. [PMID: 32222888 DOI: 10.1007/s11120-020-00736-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 03/16/2020] [Indexed: 06/10/2023]
Abstract
The damaging effects of supra-optimal irradiance on plants, often turning to be lethal, may be circumvented by chloroplast avoidance movement which realigns chloroplasts to the anticlinal surfaces of cells (parallel to the incident light), essentially minimizing photon absorption. In angiosperms and many other groups of plants, chloroplast avoidance movement has been identified to be a strong blue light (BL)-dependent process being mediated by actin filaments wherein phototropins are identified as the photoreceptor involved. Studies through the last few decades have identified key molecular mechanisms involving Chloroplast Unusual Positioning 1 (CHUP1) protein and specific chloroplast-actin (cp-actin) filaments. However, the signal transduction pathway from strong BL absorption down to directional re-localization of chloroplasts by actin filaments is complex and ambiguous. Being the immediate cellular products of high irradiance absorption and having properties of remodelling actin as well as phototropin, reactive oxygen species (ROS) deemed to be more able and prompt than any other signalling agent in mediating chloroplast avoidance movement. Although ROS are presently being identified as fundamental component for regulating different plant processes ranging from growth, development and immunity, its role in avoidance movement have hardly been explored in depth. However, few recent reports have demonstrated the direct stimulatory involvement of ROS, especially H2O2, in chloroplast avoidance movement with Ca2+ playing a pivotal role. With this perspective, the present review discusses the mechanisms of ROS-mediated chloroplast avoidance movement involving ROS-Ca2+-actin communication system and NADPH oxidase (NOX)-plasma membrane (PM) H+-ATPase positive feed-forward loop. A possible working model is proposed.
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Affiliation(s)
- Arkajo Majumdar
- Plant Physiology and Biochemistry Laboratory, Department of Botany, Visva-Bharati University, Santiniketan, West Bengal, 731235, India
- Department of Botany, City College, 102/1 Raja Rammohan Sarani, Kolkata, West Bengal, 700009, India
| | - Rup Kumar Kar
- Plant Physiology and Biochemistry Laboratory, Department of Botany, Visva-Bharati University, Santiniketan, West Bengal, 731235, India.
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Majumdar A, Kar RK. Orchestration of Cu-Zn SOD and class III peroxidase with upstream interplay between NADPH oxidase and PM H +-ATPase mediates root growth in Vigna radiata (L.) Wilczek. JOURNAL OF PLANT PHYSIOLOGY 2019; 232:248-256. [PMID: 30537611 DOI: 10.1016/j.jplph.2018.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/01/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
Post-germination plant growth depends on the regulation of reactive oxygen species (ROS) metabolism, spatiotemporal pH changes and Ca+2 homeostasis, whose potential integration has been studied during Vigna radiata (L.) Wilczek root growth. The dissipation of proton (H+) gradients across plasma membrane (PM) by CCCP (protonophore) and the inhibition of PM H+-ATPase by sodium orthovanadate repressed SOD (superoxide dismutase; EC 1.15.1.1) activity as revealed by spectrophotometric and native PAGE assay results. Similar results derived from treatment with DPI (NADPH oxidase inhibitor) and Tiron (O2- scavenger) denote a functional synchronization of SOD, PM H+-ATPase and NOX, as the latter two enzymes are substrate sources for SOD (H+ and O2-, respectively) and are involved in a feed-forward loop. After SOD inactivation, a decline in apoplastic H2O2 content was observed in each treatment group, emerging as a possible cause of the diminution of class III peroxidase (Prx; EC 1.11.1.7), which utilizes H2O2 as a substrate. In agreement with the pivotal role of Ca+2 in PM H+-ATPase and NOX activation, Ca+2 homeostasis antagonists, i.e., LaCl3 (Ca+2 channel inhibitor), EGTA (Ca+2 chelator) and LiCl (endosomal Ca+2 release blocker), inhibited both SOD and Prx. Finally, a drastic reduction in apoplastic OH (hydroxyl radical) concentrations (induced by each treatment, leading to Prx inhibition) was observed via fluorometric analysis. A consequential inhibition of root growth observed under each treatment denotes the importance of the orchestrated functioning of PM H+-ATPase, NOX, Cu-Zn SOD and Prx during root growth. A working model demonstrating postulated enzymatic synchronization with an intervening role of Ca+2 is proposed.
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Affiliation(s)
- Arkajo Majumdar
- Plant Physiology and Biochemistry Laboratory, Department of Botany, Visva-Bharati University, Santiniketan, 731235, West Bengal, India; Department of Botany, City College, 102/1 Raja Rammohan Sarani, Kolkata, 700009, West Bengal, India
| | - Rup Kumar Kar
- Plant Physiology and Biochemistry Laboratory, Department of Botany, Visva-Bharati University, Santiniketan, 731235, West Bengal, India.
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Majumdar A, Kar RK. Congruence between PM H +-ATPase and NADPH oxidase during root growth: a necessary probability. PROTOPLASMA 2018; 255:1129-1137. [PMID: 29435645 DOI: 10.1007/s00709-018-1217-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/26/2018] [Indexed: 05/12/2023]
Abstract
Plasma membrane (PM) H+-ATPase and NADPH oxidase (NOX) are two key enzymes responsible for cell wall relaxation during elongation growth through apoplastic acidification and production of ˙OH radical via O2˙-, respectively. Our experiments revealed a putative feed-forward loop between these enzymes in growing roots of Vigna radiata (L.) Wilczek seedlings. Thus, NOX activity was found to be dependent on proton gradient generated across PM by H+-ATPase as evident from pharmacological experiments using carbonyl cyanide m-chlorophenylhydrazone (CCCP; protonophore) and sodium ortho-vanadate (PM H+-ATPase inhibitor). Conversely, H+-ATPase activity retarded in response to different ROS scavengers [CuCl2, N, N' -dimethylthiourea (DMTU) and catalase] and NOX inhibitors [ZnCl2 and diphenyleneiodonium (DPI)], while H2O2 promoted PM H+-ATPase activity at lower concentrations. Repressing effects of Ca+2 antagonists (La+3 and EGTA) on the activity of both the enzymes indicate its possible mediation. Since, unlike animal NOX, the plant versions do not possess proton channel activity, harmonized functioning of PM H+-ATPase and NOX appears to be justified. Plasma membrane NADPH oxidase and H+-ATPase are functionally synchronized and they work cooperatively to maintain the membrane electrical balance while mediating plant cell growth through wall relaxation.
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Affiliation(s)
- Arkajo Majumdar
- Plant Physiology and Biochemistry Laboratory, Department of Botany, Visva-Bharati University, Santiniketan, West Bengal, 731235, India
- Department of Botany, City College, 102/1 Raja Rammohan Sarani, Kolkata, West Bengal, 700009, India
| | - Rup Kumar Kar
- Plant Physiology and Biochemistry Laboratory, Department of Botany, Visva-Bharati University, Santiniketan, West Bengal, 731235, India.
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