Plants often encounter light intensities exceeding the capacity of photosynthesis(excessive light)mainly due to biotic and abiotic factors,which lower C02 fixation and reduce light energy sinks.Under excessive light,t...Plants often encounter light intensities exceeding the capacity of photosynthesis(excessive light)mainly due to biotic and abiotic factors,which lower C02 fixation and reduce light energy sinks.Under excessive light,the photosynthetic electron transport chain generates damaging molecules,hence leading to photooxidative stress and eventually to cell death.In this review,we summarize the mechanisms linking the excessive absorption of light energy in chloroplasts to programmed cell death in plant leaves.We highlight the importance of reactive carbonyl species generated by lipid photooxidation,their detoxification,and the integrating role of the endoplasmic reticulum in the adoption of phototolerance or cell-death pathways.Finally,we invite the scientific community to standardize the conditions of excessive light treatments.展开更多
The oxidative burst is a critical early event in plant-pathogen interactions that leads to a localized, programmed cell death (PCD) called the hypersensitive response (HR). The HR and associated PCD retard infection b...The oxidative burst is a critical early event in plant-pathogen interactions that leads to a localized, programmed cell death (PCD) called the hypersensitive response (HR). The HR and associated PCD retard infection by biotrophic pathogens, but can, in fact, enhance infection by necrotrophic pathogens like Botrytis cinerea. In addition to signaling the induction of the HR, reactive oxygen species (ROS) produced during the oxidative burst are?antimicrobial. We hypothesize that pathogens such as B. cinerea survive the antimicrobial effects of ROS, at least partially by secreting the antioxidant mannitol during infection. This is supported by the previous observation that overexpression of the catabolic enzyme mannitol dehydrogenase (MTD) can decrease a plants susceptibility to mannitol-secreting pathogens like B. cinerea. To extend the above hypothesis, and test the general utility of this approach in an important horticultural crop, we overexpressed celery MTD in tomato (Solanum lycopersicum cv. “Moneymaker”). In these studies, we observed a significant increase (up to 90%) in resistance to B. cinerea in transgenic tomatoes expressing high amounts of MTD.展开更多
Abstract: Cell death is a common event in all types of plant organisms. Understanding the phenomenon of programmed cell death (PCD) is an important area of research for plant scientists because of its role in senescen...Abstract: Cell death is a common event in all types of plant organisms. Understanding the phenomenon of programmed cell death (PCD) is an important area of research for plant scientists because of its role in senescence and the post-harvest quality of ornamentals, fruits, and vegetables. In the present paper, PCD in relation to petal senescence in ornamental plants is reviewed. Morphological, anatomical, physiological, and biochemical changes that are related to PCD in petals, such as water content, sink-source relationships, hormones, genes, and signal transduction pathways, are discussed. Several approaches to improving the quality of post-harvest ornamentals are reviewed and some prospects for future research are given.展开更多
基金the French National Research Agency(ANR project SLOSAM,14-CE02-0010-02).
文摘Plants often encounter light intensities exceeding the capacity of photosynthesis(excessive light)mainly due to biotic and abiotic factors,which lower C02 fixation and reduce light energy sinks.Under excessive light,the photosynthetic electron transport chain generates damaging molecules,hence leading to photooxidative stress and eventually to cell death.In this review,we summarize the mechanisms linking the excessive absorption of light energy in chloroplasts to programmed cell death in plant leaves.We highlight the importance of reactive carbonyl species generated by lipid photooxidation,their detoxification,and the integrating role of the endoplasmic reticulum in the adoption of phototolerance or cell-death pathways.Finally,we invite the scientific community to standardize the conditions of excessive light treatments.
文摘The oxidative burst is a critical early event in plant-pathogen interactions that leads to a localized, programmed cell death (PCD) called the hypersensitive response (HR). The HR and associated PCD retard infection by biotrophic pathogens, but can, in fact, enhance infection by necrotrophic pathogens like Botrytis cinerea. In addition to signaling the induction of the HR, reactive oxygen species (ROS) produced during the oxidative burst are?antimicrobial. We hypothesize that pathogens such as B. cinerea survive the antimicrobial effects of ROS, at least partially by secreting the antioxidant mannitol during infection. This is supported by the previous observation that overexpression of the catabolic enzyme mannitol dehydrogenase (MTD) can decrease a plants susceptibility to mannitol-secreting pathogens like B. cinerea. To extend the above hypothesis, and test the general utility of this approach in an important horticultural crop, we overexpressed celery MTD in tomato (Solanum lycopersicum cv. “Moneymaker”). In these studies, we observed a significant increase (up to 90%) in resistance to B. cinerea in transgenic tomatoes expressing high amounts of MTD.
文摘Abstract: Cell death is a common event in all types of plant organisms. Understanding the phenomenon of programmed cell death (PCD) is an important area of research for plant scientists because of its role in senescence and the post-harvest quality of ornamentals, fruits, and vegetables. In the present paper, PCD in relation to petal senescence in ornamental plants is reviewed. Morphological, anatomical, physiological, and biochemical changes that are related to PCD in petals, such as water content, sink-source relationships, hormones, genes, and signal transduction pathways, are discussed. Several approaches to improving the quality of post-harvest ornamentals are reviewed and some prospects for future research are given.
