Journal
PLANT AND CELL PHYSIOLOGY
Volume 53, Issue 5, Pages 892-900Publisher
OXFORD UNIV PRESS
DOI: 10.1093/pcp/pcs032
Keywords
Chloroplast downsizing; Mesophyll conductance; Nitrogen form; Rice; Water stress
Categories
Funding
- National Natural Science Foundation of China [30671233, 30871587, 31172020]
- National Basic Research Program of China [2009CB118608]
Ask authors/readers for more resources
The phenomenon whereby ammonium enhances the tolerance of rice seedlings (Oryza sativa L., cv. 'Shanyou 63' hybrid indica China) to water stress has been reported in previous studies. To study the intrinsic mechanism of biomass synthesis related to photosynthesis, hydroponic experiments supplying different nitrogen (N) forms were conducted; water stress was simulated by the addition of polyethylene glycol. Water stress decreased leaf water potential (Psi(leaf)) under nitrate nutrition, while it had no negative effect under ammonium nutrition. The decreased Psi(leaf) under nitrate nutrition resulted in chloroplast downsizing and subsequently decreased mesophyll conductance to CO2 (g(m)). The decreased g(m) and stomatal conductance (g(s)) under nitrate nutrition with water stress restrained the CO2 supply to the chloroplast and Rubisco. The relatively higher distribution of leaf N to Rubisco under ammonium nutrition might also be of benefit for photosynthesis under water stress. In conclusion, chloroplast downsizing induced a decline in g(m), a relatively higher decrease in g(s) under nitrate nutrition with water stress, restrained the CO2 supply to Rubisco and finally decreased the photosynthetic rate.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available