chlorophyll-a and uniconazole

Phytohormones are important for the growth and development of plants. The objective of the experiment was to investigate the effect of foliar application of uniconazole (UCZ) at the four-leaf stage on hormone crosstalk and production of winter wheat. An experiment was carried out during 2015-2016 and 2016-2017 growth season in a semi-arid region, where UCZ at a concentration of 0 (CK, distilled water), 15 (FU

Topics: Chlorophyll; Photosynthesis; Triazoles; Triticum

Uniconazole (S-(+)-uniconazole), a plant growth retardant, exerts key roles in modulating growth and development and increasing abiotic stress tolerance in plants. However, the underlying mechanisms by which uniconazole regulates drought response remain largely unknown. Here, the effects of exogenous uniconazole on drought tolerance in hemp were studied via physiological and transcriptome analyses of the drought-sensitive industrial hemp cultivar Hanma No. 2 grown under drought stress. Exogenous uniconazole treatment increased hemp tolerance to drought-induced damage by enhancing chlorophyll content and photosynthesis capacity, regulating activities of enzymes involved in carbon and nitrogen metabolism, and altering endogenous hormone levels. Expression of genes associated with porphyrin and chlorophyll metabolism, photosynthesis-antenna proteins, photosynthesis, starch and sucrose metabolism, nitrogen metabolism, and plant hormone signal transduction were significantly regulated by uniconazole compared with that by control (distilled water) under drought stress. Numerous genes were differentially expressed to increase chlorophyll content, enhance photosynthesis, regulate carbon-nitrogen metabolism-related enzyme activities, and alter endogenous hormone levels. Thus, uniconazole regulated physiological and molecular characteristics of photosynthesis, carbon-nitrogen metabolism, and plant hormone signal transduction to enhance drought resistance in industrial hemp.

Topics: Cannabis; Carbohydrate Metabolism; Carbon; Chlorophyll; Droughts; Enzymes; Fungicides, Industrial; Gene Expression Profiling; Gene Expression Regulation, Plant; Nitrogen; Photosynthesis; Plant Growth Regulators; Plant Proteins; Porphyrins; Stress, Physiological; Triazoles

This study investigated whether uniconazole confers drought tolerance to soybean and if such tolerance is correlated with changes in photosynthesis, hormones and antioxidant system of leaves. Soybean plants were foliar treated with uniconazole at 50 mg L-1 at the beginning of bloom and then exposed to water deficit stress at pod initiation for 7 d. Uniconazole promoted biomass accumulation and seed yield under both water conditions. Plants treated with uniconazole showed higher leaf water potential only in water-stressed condition. Water stress decreased the chlorophyll content and photosynthetic rate, but those of uniconazole-treated plants were higher than the stressed control. Uniconazole increased the maximum quantum yield of photosystemand ribulose-1,5-bisphosphate carboxylase/oxygenase activity of water-stressed plants. Water stress decreased partitioning of assimilated 14C from labeled leaf to the other parts of the plant. In contrast, uniconazole enhanced translocation of assimilated 14C from labeled leaves to the other parts, except stems, regardless of water treatment. Uniconazole-treated plants contained less GA3, GA4 and ABA under well-watered condition than untreated plants, while the IAA and zeatin levels were increased substantially under both water conditions, and ABA concentration was also increased under water stressed condition. Under water-stressed conditions, uniconazole increased the content of proline and soluble sugars, and the activities of superoxide dismutase and peroxidase in soybean leaves but not the malondialdehyde content or electrical conductivity. These results suggest that uniconazole-induced tolerance to water deficit stress in soybean was related to the changes of photosynthesis, hormones and antioxidant system of leaves.

Topics: Abscisic Acid; Antioxidants; Carbohydrate Metabolism; Carbon; Carbon Radioisotopes; Chlorophyll; Electric Conductivity; Gibberellins; Glycine max; Photosynthesis; Plant Growth Regulators; Plant Leaves; Plant Proteins; Proline; Ribulose-Bisphosphate Carboxylase; Triazoles; Water