Anatomical variation of mesophyll conductance under potassium deficiency has a vital role in determining leaf photosynthesis.

Autor: Lu Z; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Wuhan, 430070, China.; Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China., Lu J; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Wuhan, 430070, China.; Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China., Pan Y; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Wuhan, 430070, China.; Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China., Lu P; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Wuhan, 430070, China.; Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China., Li X; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Wuhan, 430070, China.; Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China., Cong R; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Wuhan, 430070, China.; Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China., Ren T; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Wuhan, 430070, China. rentao@mail.hzau.edu.cn.; Microelement Research Center, Huazhong Agricultural University, Wuhan, 430070, China. rentao@mail.hzau.edu.cn.
Jazyk: angličtina
Zdroj: Plant, cell & environment [Plant Cell Environ] 2016 Nov; Vol. 39 (11), pp. 2428-2439. Date of Electronic Publication: 2016 Sep 13.
DOI: 10.1111/pce.12795
Abstrakt: Leaves exposed to potassium (K) deficiency usually present decreased mesophyll conductance (g m ) and photosynthesis (A). The relative contributions of leaf anatomical traits in determining g m have been quantified; however, anatomical variabilities related to low g m under K starvation remain imperfectly known. A one-dimensional model was used to quantify anatomical controls of the entire CO 2 diffusion pathway resistance within a leaf on two Brassica napus L. cultivars in response to K deficiency. Leaf photosynthesis of both cultivars was significantly decreased under K deficiency in parallel with down-regulated g m . The mesophyll conductance limitation contributed to more than one-half of A decline. The decreased internal air space in K-starved leaves was associated with the increase of gas-phase resistance. Potassium deficiency reduced liquid-phase conductance by decreasing the exposed surface area of chloroplasts per unit leaf area (S c /S), and enlarging the resistance of the cytoplasm that can be interpreted by the increasing distance of chloroplast from cell wall, and between adjacent chloroplasts. Additionally, the discrepancies of A between two cultivars were in part because of g m variations, ascribing to an altered S c /S. These results emphasize the important role of K on the regulation of g m by enhancing S c /S and reducing cytoplasm resistance.
(© 2016 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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