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Plant physiology
About: Plant physiology is a research topic. Over the lifetime, 1537 publications have been published within this topic receiving 72038 citations.
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TL;DR: The results underscore the risks for plant growth of β-lactam antibiotics in agricultural soils, and suggest a possible function for these compounds as fungus-produced signaling molecules to modify plant behavior.
Abstract: The presence of antibiotics in soils could be due to natural production by soil microorganisms or to the effect of anthropogenic activities. However, the impact of these compounds on plant physiology has not been thoroughly investigated. To evaluate the effect of β-lactam antibiotics (carbenicillin and penicillin) on the growth and development of Arabidopsis thaliana roots, plants were grown in the presence of different amounts and we found a reduction in root size, an increase in the size of root hairs as well as an abnormal position closer to the tip of the roots. Those phenomena were dependent on the accumulation of both antibiotics inside root tissues and also correlated with a decrease in size of the root apical meristem not related to an alteration in cell division but to a decrease in cell expansion. Using an RNA sequencing analysis, we detected an increase in the expression of genes related to the response to oxidative stress, which would explain the increase in the levels of endogenous reactive oxygen species found in the presence of those antibiotics. Moreover, some auxin-responsive genes were misregulated, especially an induction of CYP79B3, possibly explaining the increase in auxin levels in the presence of carbenicillin and the decrease in the amount of indole glucosinolates, involved in the control of fungal infections. Accordingly, penicillin-treated plants were hypersensitive to the endophyte fungus Colletotrichum tofieldiae. These results underscore the risks for plant growth of β-lactam antibiotics in agricultural soils, and suggest a possible function for these compounds as fungus-produced signaling molecules to modify plant behavior.
15 citations
Patent•
10 Dec 2002
TL;DR: In this article, the authors proposed methods for stimulating root growth and enhancing the formation of lateral or adventitious roots and/or altering root geotropism comprising expression of a plant cytokinin oxidase in plants or plant parts.
Abstract: The present invention relates to methods for stimulating root growth and/or enhancing the formation of lateral or adventitious roots and/or altering root geotropism comprising expression of a plant cytokinin oxidase in plants or plant parts. Also provided by the present invention are methods for increasing seed size and/or weight, embryo size and/or weight, and cotyledon size and/or weight. The methods comprise expression of a plant cytokinin oxidase or expression of another protein that reduces the level of active cytokinins in plants or plant parts.The invention also relates to novel plant cytokinin oxidase proteins, nucleic acid sequences encoding cytokinin oxidase proteins as well as to vectors, host cells, transgenic cells and plants comprising said sequences. The invention also relates to the use of said sequences for improving root-related characteristics including increasing yield and/or enhancing early vigor and/or modifying root/shoot ratio and/or improving resistance to lodging and/or increasing drought tolerance and/or promoting in vitro propagation of explants and/or modifying cell fate and/or plant development and/or plant morphology and/or plant biochemistry and/or plant physiology. The invention also relates to the use of said sequences in the above-mentioned methods.The invention also relates to methods for identifying and obtaining proteins and compounds interacting with cytokinin oxidase proteins. The invention also relates to the use of said compounds as a plant growth regulator or herbicide.
15 citations
TL;DR: The action of a non-photosynthetic photoreceptor in the control of cell-wall polysaccharide synthesis is suggested because the accumulation ofcell-wallpolysaccharides was not correlated with net photosynthesis in contrast to what occurred with carbon, chlorophyll and phycoerythrin accumulation.
Abstract: The influence of different light qualities on the photosynthetic rate, dark respiration, intracellular carbon and nitrogen content, and accumulation of photosynthetic pigments and cell-wall polysaccharides during short-term incubation (5 h) of the red algaGelidium sesquipedale was investigated. The same photon irradiance of 50μmol m−2 s−2 below the light saturation point of photosynthesis was applied in each case. Blue light stimulated photosynthesis, dark respiration and the accumulation of chlorophyll and biliproteins, phycoerythrin in particular. The accumulation of internal carbon and nitrogen was greater under blue light than under the other light qualities. In contrast, the percentage of cell-wall polysaccharides was higher in red light. The content of cell-wall polysaccharides decreased during the time of incubation in all light treatments except in red light. The action of a non-photosynthetic photoreceptor in the control of cell-wall polysaccharide synthesis is suggested because the accumulation of cell-wall polysaccharides was not correlated with net photosynthesis in contrast to what occurred with carbon, chlorophyll and phycoerythrin accumulation.
15 citations
TL;DR: The results are discussed in terms of the transition from the ‘high irradiance reaction’ of young seedlings to a possible steady state of phytochrome control in the mature plant.
Abstract: Summary
In 40 h old cotyledons of etiolated Sinapis alba (L.) red/far-red photoreversibility and the effect of continuous far-red light were used to demonstrate the involvement of phytochrome in the control of in vivo nitrate reductase activity and anthocyanin synthesis. Over a period of several days during the development of S. alba seedlings, in the light, in vivo nitrate reductase activity and anthocyanin synthesis were determined in the cotyledons and hypocotyls. Seedlings were grown under two light environments; fluorescent white light, establishing an estimated phytochrome photo-equilibrium, φE, of 0.69, simulating direct sunlight and fluorescent white light with added far-red light, establishing an estimated phytochrome photo-equilibrium of 0.26, simulating ‘shade’ or ‘canopy’ light. The time courses of both responses were greatly influenced by these different light qualities. Furthermore, in the case of nitrate reductase activity the cotyledons and hypocotyls showed marked differences in their responses to light quality. In the cotyledons a light source establishing a low photo-equilibrium was initially more effective in eliciting the response, but with time, a light source establishing a high photo-equilibrium became the more effective. In the hypocotyls a light source establishing a high photo-equilibrium was always the more effective. The anthocyanin response showed the crossing over of effectiveness of high and low photo-equilibrium in both tissues. The results are discussed in terms of the transition from the ‘high irradiance reaction’ of young seedlings to a possible steady state of phytochrome control in the mature plant.
15 citations