{"title":"Phosphate Foliar Fertilization Can Alleviate Water Deficit Effects on Photosynthesis and Yield","authors":"Pimentel, Carlos","doi":"10.54026/esecr/1050","DOIUrl":null,"url":null,"abstract":"Slight dehydration of the plant will cause a reduction in cell turgor, especially in leaves, which will immediately paralyze cell growth and protein biosynthesis and decrease the stomatal aperture [1]. In addition, the limitation of CO 2 Assimilation Rate (A) under drought could also be due to the inhibition of Ribulose,1-5, Bisphosphate synthesis because the low ATP content in the chloroplast caused by the loss of ATP synthase activity and inorganic Phosphate (Pi) content in the chloroplast [3]. Therefore, A will be reduced, but not entirely, and carbohydrates synthesis will slow but continue. However, sucrose will not be exported for the growth of other tissues; it will be used only to maintain cell respiration, causing an accumulation of soluble sugars-P in the leaves’ cells [2]. If the water deficit occurs at the pollination stage, the reduction in A and sucrose export for the reproductive organs will cause embryo abortion because of the lack of soluble sugars-P to maintain embryo growth [1]. However, due to growth arrest, sugars-P accumulation in the photosynthetic cells can stop Triose-Phosphate (Triose-P) export from the chloroplast due to the low availability of Pi in the cytoplasm. The export of Triose-P is done by Phosphate Translocator (PT) antiporter in exchange of Pi, and it is controlled by Fructose-2,6-Phosphate (F-2,6-P) concentration in the cytoplasm, which is increased by growth arrest under drought [4]. Therefore, three experiments were conducted with common bean (Phaseolus vulgaris L.) plants to evaluate when applying the Pi in the first and the effect of Pi foliar fertilization on A and yield in the two others. The common bean is an important source of proteins in Latin America. However, it is considered a poor soil phosphorus extractor due to its small root system, with (Ac) of rehydrated A320 with foliar Pi supply was also higher than for non-Pi-supplied plants. There were no significant differences for yield components of Pi supplied genotypes water stressed plants compared to control plants. However, after the drought, the dry seed weight of both genotypes with Pi supply was very close to that of control plants irrigated continuously, but not significantly. In addition, water stressed Ouro Negro without Pi supply presented a significant reduction in dry seed weight compared to control plants irrigated continuously [5]. The results revealed an up-regulation of the recovery of photosynthesis after water deficit induced by the foliar Pi supply, which can increase some yield components in this condition, but it was genotype-specific.","PeriodicalId":140386,"journal":{"name":"Environmental Sciences and Ecology: Current Research (ESECR","volume":"70 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2022-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Sciences and Ecology: Current Research (ESECR","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.54026/esecr/1050","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Slight dehydration of the plant will cause a reduction in cell turgor, especially in leaves, which will immediately paralyze cell growth and protein biosynthesis and decrease the stomatal aperture [1]. In addition, the limitation of CO 2 Assimilation Rate (A) under drought could also be due to the inhibition of Ribulose,1-5, Bisphosphate synthesis because the low ATP content in the chloroplast caused by the loss of ATP synthase activity and inorganic Phosphate (Pi) content in the chloroplast [3]. Therefore, A will be reduced, but not entirely, and carbohydrates synthesis will slow but continue. However, sucrose will not be exported for the growth of other tissues; it will be used only to maintain cell respiration, causing an accumulation of soluble sugars-P in the leaves’ cells [2]. If the water deficit occurs at the pollination stage, the reduction in A and sucrose export for the reproductive organs will cause embryo abortion because of the lack of soluble sugars-P to maintain embryo growth [1]. However, due to growth arrest, sugars-P accumulation in the photosynthetic cells can stop Triose-Phosphate (Triose-P) export from the chloroplast due to the low availability of Pi in the cytoplasm. The export of Triose-P is done by Phosphate Translocator (PT) antiporter in exchange of Pi, and it is controlled by Fructose-2,6-Phosphate (F-2,6-P) concentration in the cytoplasm, which is increased by growth arrest under drought [4]. Therefore, three experiments were conducted with common bean (Phaseolus vulgaris L.) plants to evaluate when applying the Pi in the first and the effect of Pi foliar fertilization on A and yield in the two others. The common bean is an important source of proteins in Latin America. However, it is considered a poor soil phosphorus extractor due to its small root system, with (Ac) of rehydrated A320 with foliar Pi supply was also higher than for non-Pi-supplied plants. There were no significant differences for yield components of Pi supplied genotypes water stressed plants compared to control plants. However, after the drought, the dry seed weight of both genotypes with Pi supply was very close to that of control plants irrigated continuously, but not significantly. In addition, water stressed Ouro Negro without Pi supply presented a significant reduction in dry seed weight compared to control plants irrigated continuously [5]. The results revealed an up-regulation of the recovery of photosynthesis after water deficit induced by the foliar Pi supply, which can increase some yield components in this condition, but it was genotype-specific.