Wilting

About: Wilting is a research topic. Over the lifetime, 1906 publications have been published within this topic receiving 35462 citations.

The reflectance at the 950-970 nm region as an indicator of plant water status

Abstract: We present new remote sensing indices of plant water status: the ratio between the reflectance at 970 nm, one of the water absorption bands, and the reflectance at a reference wavelength, 900 nm (R970/R9000; the first derivative minimum in this near-infrared region (dNIRminimum ) and the wavelength where this minimum is found ( λNIRminimum). In order to evaluate them, we carried out three experiments. Daily irrigated gerbera plants were allowed to dry until almost wilting and then daily irrigation was restarted; pepper and bean plants were grown for four months submitted to two different irrigation treatments; and bean detached leaves were submitted to progressive dehydration whereas pressure-volume curves were being carried out. In gerbera plants, the trough about 950–970 nm decreased as the drought was increasing. Therefore, the R970/R900 index and the dNIRminimum closely tracked the changes in relative water content (RWC), leaf water potential, stomatal conductance and the foliage-air temperat...

Role of Ethylene in Senescence of Petals—Morphological and Taxonomical Relationships

Abstract: Woltering, E. J. and Van Doom, W. G. 1988. Role of ethylene in senescence of petals—morphological and taxonomical relationships.—J. exp. Bot. 39: 1605-1616. Petal senescence in mature flowers was studied in 93 species from 22 families. The initial symptom of senescence was either wilting or abscission, but in some species the time span between wilting and abscission was very short. There was no apparent relationship between corolla form (choripetalous or sympetalous), ovary position (inferior or superior with respect to the corolla) and type of senescence (initial wilting or initial abscission). In monocots no initial abscission was found, while in dicots the difference between the wilting type and the abscission type was generally at the family level. With respect to petal senescence, sensitivity to exogenous ethylene (C2H4) was also related to the family level. Except for a few families (all tested Campanulaceae, Caryophyllaceae and Malvaceae, and most Orchidaceae), most of the flowers investigated that showed initial wilting were not sensitive to exogenous ethylene, e.g. all tested Compositae, Iridaceae, and Liliaceae. Most of the flowers showing initial abscission were sensitive to exogenous ethylene (Geraniaceae, Labiatae, Ranunculaceae, Rosaceae, Scrophulariaceae). Experiments with silver thiosulphate (STS) confirmed the effects of exogenous ethylene, both in flowers showing initial wilting and in flowers showing initial abscission. The data indicate, therefore, that ethylene is involved in the natural senescence of only a minority of the wilting type of flowers and in a majority (if not all) of the abscising type of flowers. Key words—Abscission, ethylene, senescence, silver thiosulphate.

The correlations and sequence of plant stomatal, hydraulic, and wilting responses to drought

Abstract: Climate change is expected to exacerbate drought for many plants, making drought tolerance a key driver of species and ecosystem responses. Plant drought tolerance is determined by multiple traits, but the relationships among traits, either within individual plants or across species, have not been evaluated for general patterns across plant diversity. We synthesized the published data for stomatal closure, wilting, declines in hydraulic conductivity in the leaves, stems, and roots, and plant mortality for 262 woody angiosperm and 48 gymnosperm species. We evaluated the correlations among the drought tolerance traits across species, and the general sequence of water potential thresholds for these traits within individual plants. The trait correlations across species provide a framework for predicting plant responses to a wide range of water stress from one or two sampled traits, increasing the ability to rapidly characterize drought tolerance across diverse species. Analyzing these correlations also identified correlations among the leaf and stem hydraulic traits and the wilting point, or turgor loss point, beyond those expected from shared ancestry or independent associations with water stress alone. Further, on average, the angiosperm species generally exhibited a sequence of drought tolerance traits that is expected to limit severe tissue damage during drought, such as wilting and substantial stem embolism. This synthesis of the relationships among the drought tolerance traits provides crucial, empirically supported insight into representing variation in multiple traits in models of plant and ecosystem responses to drought.

(+)-Abscisic Acid, the Growth Inhibitor induced in Detached Wheat Leaves by a Period of Wilting

Abstract: WHEN excised wheat leaves are maintained in a wilted condition for a period of hours there is a considerable increase in the content of an acidic ether-soluble growth inhibiting substance1. Because of its acidic nature and its RF in several solvent systems, (+)-abscisic acid (ABA) was suspected to be this substance. This has now been confirmed by optical rotatory dispersion.

Bacterial Modulation of Plant Ethylene Levels

Abstract: A focus on the mechanisms by which ACC deaminase-containing bacteria facilitate plant growth.Bacteria that produce the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, when present either on the surface of plant roots (rhizospheric) or within plant tissues (endophytic), play an active role in modulating ethylene levels in plants. This enzyme activity facilitates plant growth especially in the presence of various environmental stresses. Thus, plant growth-promoting bacteria that express ACC deaminase activity protect plants from growth inhibition by flooding and anoxia, drought, high salt, the presence of fungal and bacterial pathogens, nematodes, and the presence of metals and organic contaminants. Bacteria that express ACC deaminase activity also decrease the rate of flower wilting, promote the rooting of cuttings, and facilitate the nodulation of legumes. Here, the mechanisms behind bacterial ACC deaminase facilitation of plant growth and development are discussed, and numerous examples of the use of bacteria with this activity are summarized.