title: Regulation of 2,4-epibrassinolide on mineral nutrient uptake and ion distribution in Ca(NO3)2 stressed cucumber plants.
abstract: 2,4-Epibrassinolide (EBL) is a plant hormone that plays a pivotal role in regulation of plants growth and development processes under abiotic stress. The investigation was carried out to study the effect of EBL on mineral nutrients uptake and distribution with ion element analysis and X-ray microanalysis in cucumber seedlings (Cucumis sativus L. cv. Jinyou No.4) under 80 mM Ca(NO3)2 stress. Our study found EBL significantly alleviated the inhibitory of P, K, Na, Mg, Fe, Mn, or Cl uptake in shoot or root by Ca(NO3)2 stress. Under Ca(NO3)2 stress, X-ray microanalysis showed that high levels of Ca by EBL treatment accumulated in the epidermal cells of root and gradually decreased from epidermal cells to stellar parenchyma. K(+) levels were restored in different cross section of roots and high K(+) level mostly accumulated in stellar parenchyma. The results of Ca(2+) ultra-structural localization showed Ca(2+) particles of antimonite precipitate by EBL were partly decreased in mesophyll and root cells, and Ca(2+) precipitate distributed in intercellular spaces again. Increased Ca(2+)-ATPase activity and ATP content by EBL were also contributed to extrude excess Ca(2+) from the cytoplasm. These results suggested that EBL could alleviate the ion damage from excess Ca(2+) through regulating mineral nutrients uptake and distribution.
authors.affiliation: College of Horticulture, Anhui Agricultural University, Hefei 230061, China; College of Horticulture, Nanjing Agricultural University, Key Laboratory of Southern Vegetable Crop Genetic Improvement, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Lingyun
authors.initials: L
authors.lastname: Yuan
authors.affiliation: College of Horticulture, Anhui Agricultural University, Hefei 230061, China.
authors.forename: Shidong
authors.initials: S
authors.lastname: Zhu
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Key Laboratory of Southern Vegetable Crop Genetic Improvement, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Shu
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Key Laboratory of Southern Vegetable Crop Genetic Improvement, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Sun
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Key Laboratory of Southern Vegetable Crop Genetic Improvement, Ministry of Agriculture, Nanjing 210095, China. Electronic address: srguo@njau.edu.cn.
authors.forename: Shirong
authors.initials: S
authors.lastname: Guo
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D060406:Brassinosteroids / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D017610:Calcium Compounds / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D018553:Cucumis sativus / Q000502:physiology*; D006706:Homeostasis; D007477:Ions / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000502:physiology; D018520:Plant Shoots / Q000502:physiology; D013260:Steroids, Heterocyclic / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D060406:Brassinosteroids; D017610:Calcium Compounds; D007477:Ions; D009566:Nitrates; D010937:Plant Growth Regulators; D013260:Steroids, Heterocyclic; D000255:Adenosine Triphosphate; D000252:Calcium-Transporting ATPases; C059948:calcium nitrate; D002118:Calcium; C023623:brassinolide
keywords: 2,4-epibrassinolide; ATP; Ca(2+); Ca(2+)-ATPase; ion distribution; mineral nutrient