Guttation is the exudation of drops of xylemsap on the tips or edges of leaves of some vascular plants, such as grasses, and a number of fungi, which are not plants but were previously categorized as such and studied as part of botany.
At night, transpiration usually does not occur, because most plants have their stomata closed. When there is a high soil moisture level, water will enter plant roots, because the water potential of the roots is lower than in the soil solution. The water will accumulate in the plant, creating a slight root pressure. The root pressure forces some water to exude through special leaf tip or edge structures, hydathodes or water glands, forming drops. Root pressure provides the impetus for this flow, rather than transpirational pull. Guttation is most noticeable when transpiration is suppressed and the relative humidity is high, such as during the night.
Guttation formation in fungi is important for visual identification, but the process causing it is unknown. However, due to its association with stages of rapid growth in the life cycle of fungi, it has been hypothesised that during rapid metabolism excess water produced by respiration is exuded.[1]
Chemical contentedit
Guttation fluid may contain a variety of organic and inorganic compounds, mainly sugars, and potassium.[2] On drying, a white crust remains on the leaf surface.
Girolami et al. (2009) found that guttation drops from corn plants germinated from neonicotinoid-coated seeds could contain amounts of insecticide consistently higher than 10 mg/L, and up to 200 mg/L for the neonicotinoidimidacloprid. Concentrations this high are near those of active ingredients applied in field sprays for pest control and sometimes even higher. It was found that when bees consume guttation drops collected from plants grown from neonicotinoid-coated seeds, they die within a few minutes.[3] This phenomenon may be a factor in bee deaths and, consequently, colony collapse disorder.
^Parmasto, Erast; Voitk, Andrus (2010). "Why do mushrooms weep?". FUNGI. 3 (4).
^Goatley, James L.; Lewis, Ralph W. (March 1966). "Composition of Guttation Fluid from Rye, Wheat, and Barley Seedlings". Plant Physiology. 41 (3): 373–375. doi:10.1104/pp.41.3.373. PMC1086351. PMID 16656266.
^Girolami, V.; Mazzon L.; Squartini A.; Mori N.; Marzaro M.; Di Bernardo A.; Greatti M.; Giorio C.; A Tapparos (2009). "Translocation of Neonicotinoid Insecticides From Coated Seeds to Seedling Guttation Drops: A Novel Way of Intoxication for Bees". Journal of Economic Entomology. 102 (5): 1808–1815. doi:10.1603/029.102.0511. PMID 19886445. S2CID 16692336.
February 16, 2024
guttation, exudation, drops, xylem, tips, edges, leaves, some, vascular, plants, such, grasses, number, fungi, which, plants, were, previously, categorized, such, studied, part, botany, equisetum, contents, process, chemical, content, nitrogen, levels, also, r. Guttation is the exudation of drops of xylem sap on the tips or edges of leaves of some vascular plants such as grasses and a number of fungi which are not plants but were previously categorized as such and studied as part of botany Guttation on Equisetum sp Contents 1 Process 2 Chemical content 2 1 Nitrogen levels 3 See also 4 ReferencesProcess edit nbsp Crimson guttation droplets on the tooth fungus Hydnellum peckii nbsp Guttation on a strawberry leaf nbsp Guttation on a prayer plantAt night transpiration usually does not occur because most plants have their stomata closed When there is a high soil moisture level water will enter plant roots because the water potential of the roots is lower than in the soil solution The water will accumulate in the plant creating a slight root pressure The root pressure forces some water to exude through special leaf tip or edge structures hydathodes or water glands forming drops Root pressure provides the impetus for this flow rather than transpirational pull Guttation is most noticeable when transpiration is suppressed and the relative humidity is high such as during the night Guttation formation in fungi is important for visual identification but the process causing it is unknown However due to its association with stages of rapid growth in the life cycle of fungi it has been hypothesised that during rapid metabolism excess water produced by respiration is exuded 1 Chemical content editGuttation fluid may contain a variety of organic and inorganic compounds mainly sugars and potassium 2 On drying a white crust remains on the leaf surface Girolami et al 2009 found that guttation drops from corn plants germinated from neonicotinoid coated seeds could contain amounts of insecticide consistently higher than 10 mg L and up to 200 mg L for the neonicotinoid imidacloprid Concentrations this high are near those of active ingredients applied in field sprays for pest control and sometimes even higher It was found that when bees consume guttation drops collected from plants grown from neonicotinoid coated seeds they die within a few minutes 3 This phenomenon may be a factor in bee deaths and consequently colony collapse disorder Nitrogen levels edit If high levels of nitrogen appear in the fluid it is a sign of fertilizer burn citation needed See also editHomeostasis Osmosis Soil plant atmosphere continuumReferences edit nbsp Wikimedia Commons has media related to Guttation Parmasto Erast Voitk Andrus 2010 Why do mushrooms weep FUNGI 3 4 Goatley James L Lewis Ralph W March 1966 Composition of Guttation Fluid from Rye Wheat and Barley Seedlings Plant Physiology 41 3 373 375 doi 10 1104 pp 41 3 373 PMC 1086351 PMID 16656266 Girolami V Mazzon L Squartini A Mori N Marzaro M Di Bernardo A Greatti M Giorio C A Tapparos 2009 Translocation of Neonicotinoid Insecticides From Coated Seeds to Seedling Guttation Drops A Novel Way of Intoxication for Bees Journal of Economic Entomology 102 5 1808 1815 doi 10 1603 029 102 0511 PMID 19886445 S2CID 16692336 Retrieved from https en wikipedia org w index php title Guttation amp oldid 1185528928, wikipedia, wiki, book, books, library,
