title: Effects of High Toxic Boron Concentration on Protein Profiles in Roots of Two Citrus Species Differing in Boron-Tolerance Revealed by a 2-DE Based MS Approach.
abstract: Citrus are sensitive to boron (B)-toxicity. In China, B-toxicity occurs in some citrus orchards. So far, limited data are available on B-toxicity-responsive proteins in higher plants. Thirteen-week-old seedlings of "Sour pummelo" (Citrus grandis) and "Xuegan" (Citrus sinensis) was fertilized every other day until dripping with nutrient solution containing 10 μM (control) or 400 μM (B-toxicity) H3BO3for 15 weeks. The typical B-toxic symptom only occurred in 400 μM B-treatedC. grandisleaves, and that B-toxicity decreased root dry weight more inC. grandisseedlings than inC. sinensisones, demonstrating thatC. sinensiswas more tolerant to B-toxicity thanC. grandis. Using a 2-dimensional electrophoresis (2-DE) based MS approach, we identified 27 up- and four down-accumulated, and 28 up- and 13 down-accumulated proteins in B-toxicC. sinensisandC. grandisroots, respectively. Most of these proteins were isolated only from B-toxicC. sinensisorC. grandisroots, only nine B-toxicity-responsive proteins were shared by the two citrus species. Great differences existed in B-toxicity-induced alterations of protein profiles betweenC. sinensisandC. grandisroots. More proteins related to detoxification were up-accumulated in B-toxicC. grandisroots than in B-toxicC. sinensisroots to meet the increased requirement for the detoxification of the more reactive oxygen species and other toxic compounds such as aldehydes in the former. For the first time, we demonstrated that the active methyl cycle was induced and repressed in B-toxicC. sinensisandC. grandisroots, respectively, and thatC. sinensisroots had a better capacity to keep cell wall and cytoskeleton integrity thanC. grandisroots in response to B-toxicity, which might be responsible for the higher B-tolerance ofC. sinensis. In addition, proteins involved in nucleic acid metabolism, biological regulation and signal transduction might play a role in the higher B-tolerance ofC. sinensis.
authors.affiliation: Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry UniversityFuzhou, China; College of Horticulture, Fujian Agriculture and Forestry UniversityFuzhou, China; Agriculture, Forestry and Water Conservancy Bureau of Xinzhou DistrictShangrao, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Sang
authors.affiliation: Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University Fuzhou, China.
authors.forename: Zeng-Rong
authors.initials: ZR
authors.lastname: Huang
authors.affiliation: Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University Fuzhou, China.
authors.forename: Lin-Tong
authors.initials: LT
authors.lastname: Yang
authors.affiliation: Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University Fuzhou, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Guo
authors.affiliation: Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry University Fuzhou, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.affiliation: Institute of Plant Nutritional Physiology and Molecular Biology, College of Resources and Environment, Fujian Agriculture and Forestry UniversityFuzhou, China; Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry UniversityFuzhou, China; The Higher Educational Key Laboratory of Fujian Province for Soil Ecosystem Health and Regulation, Fujian Agriculture and Forestry UniversityFuzhou, China.
authors.forename: Li-Song
authors.initials: LS
authors.lastname: Chen
keywords: 2-DE; Citrus grandis; Citrus sinensis; boron-toxicity; proteome; roots