title: Effects of different water management options and fertilizer supply on photosynthesis, fluorescence parameters and water use efficiency of Prunella vulgaris seedlings.
abstract: BACKGROUND
  Prunella vulgaris L. is a medical plant cultivated in sloping, sun-shaded areas in China. Recently, owing to air-environmental stress, especially drought stress strongly inhibits plant growth and development, the appropriate fertilizer supply can alleviate these effects. However, these is little information about their effects on P. vulgaris growing in arid and semi-arid areas with limited water and fertilizer supply.
  
  
  RESULTS
  In this study, water stress decreased the photosynthetic pigment contents, inhibited photosynthetic efficiency, induced photodamage in photosystem 2 (PS2), and decreased leaf instantaneous WUE (WUEi). The decreased net photosynthetic rate (Pn) under medium drought stress compared with the control might result from stomatal limitations. However, fertilizer supply improved photosynthetic capacity by increasing the photosynthetic pigment contents and enhancing photosynthetic efficiency under water deficit. Moreover, medium fertilization also increased WUEi under the two water conditions, but fertilizer supply did little to alleviate the PS2 photodamage caused by drought stress. Hence, drought stress was the primary limitation in the photosynthetic process of P. vulgaris seedlings, while the photosynthetic characteristics of the seedlings exhibited positive responses to fertilizer supply.
  
  
  CONCLUSIONS
  Appropriate fertilizer supply is recommended to improve photosynthetic efficiency, enhance WUEi and alleviate photodamage under drought stress.
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. chenyuhang221@126.com.|College of Pharmaceutical Sciences, Chengdu Medical College, Chengdu, 610083, People's Republic of China. chenyuhang221@126.com.
authors.forename: Yuhang
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. 1367109826@qq.com.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. gqs@njau.edu.cn.
authors.forename: Qiaosheng
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. 1393185153@qq.com.
authors.forename: Zaibiao
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. 1368281422@qq.com.
authors.forename: Lixia
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000704:Analysis of Variance; D002734:Chlorophyll / Q000502:physiology; D002940:Circadian Rhythm; D055864:Droughts; D005308:Fertilizers; D005453:Fluorescence; D010788:Photosynthesis / Q000502:physiology*; D018515:Plant Leaves; D031347:Prunella / Q000254:growth & development*; D036226:Seedlings / Q000254:growth & development*; D013312:Stress, Physiological; D013997:Time Factors; D014867:Water / Q000502:physiology*
chemical_list: D005308:Fertilizers; D014867:Water; D002734:Chlorophyll