Response of photosynthesis and carbon/nitrogen metabolism to drought stress in Chinese chestnut 'Yanshanzaofeng' seedlings

Drought is a main factor affecting the growth and yield of Chinese chestnut trees in Yan-shan Mountains. To investigate the responses of chestnut seedlings to drought stress, the growth and physiological indices, including photosynthetic characteristics, biomass, proline, malondialdehyde, carbon and nitrogen contents were measured in roots, stems, and leaves after the Chinese chestnut 'Yanshanzaofeng' seedlings in the pots were treated by simulating drought for 22 days. The results showed that, compared with the normal irrigation, water contents in the roots, stems and leaves were decreased by 18.3%, 29.0% and 62.8%, respectively, accompanied by the considerable increases in the contents of proline (355.0%-1586.7%) and malondialdehyde except in the stems (41.1%-81.3%). The non-photochemical quenching coefficiency and net photosynthetic rate in the leaves were significantly decreased by 49.4% and 77.4%, respectively. The contents of non-structural carbohydrates were increased by 21.4% in stems and 69.5% in lea