The morphology, physiology and nutritional quality of lettuce grown under hypobaria and hypoxia

Abstract The objectives of this research were to investigate the morphological, physiological and nutritional characteristics of lettuce plants (Lactuca sativa L. cv. Rome) under hypobaric and hypoxic conditions. Plants were grown under two levels of total pressures (101 and 30 kPa) and three levels of oxygen partial pressures (21, 6 and 2 kPa) for 20 days. Hypoxia (6 or 2 kPa) not only significantly inhibited the growth of lettuce plants by decreasing biomass, leaf area, root/shoot ratio, water content, the contents of minerals and organic compounds (vitamin C, crude protein and crude fat), but also destroyed the ultrastructure of mitochondria and chloroplast. The activities of catalase and total superoxide dismutase, the contents of glutathione and the total antioxidant capacity significantly decreased due to hypoxia. Hypobaria (30 kPa) did not markedly enhance the biomass, but it increased leaf area, root/shoot ratio and relative water content. Hypobaria also decreased the contents of total phenols, malondialdehyde and total carbohydrate and protected the ultrastructure of mitochondria and chloroplast under hypoxia. Furthermore, the activities of catalase and total superoxide dismutase, the contents of minerals and organic compounds markedly increased under hypobaria. This study demonstrates that hypobaria (30 kPa) does not increase the growth of lettuce plants, but it enhances plant׳s stress resistance and nutritional quality under hypoxia.

[1]  A. Bown,et al.  The Synthesis of [gamma]-Aminobutyric Acid in Response to Treatments Reducing Cytosolic pH , 1994, Plant physiology.

[2]  J. G. Scandalios.  Oxygen Stress and Superoxide Dismutases , 1993, Plant physiology.

[3]  Robert J Ferl,et al.  Hypobaric Biology: Arabidopsis Gene Expression at Low Atmospheric Pressure1[w] , 2004, Plant Physiology.

[4]  R. Ferl,et al.  Exposure of Arabidopsis thaliana to hypobaric environments: implications for low-pressure bioregenerative life support systems for human exploration missions and terraforming on Mars. , 2006, Astrobiology.

[5]  Feng Gao,et al.  Effects of low pressure and hypoxia on growth and development of wheat , 2008 .

[6]  M. Musgrave,et al.  Changes in soluble sugar, starch, and alcohol dehydrogenase in Arabidopsis thaliana exposed to N2 diluted atmospheres. , 1997, Plant & cell physiology.

[7]  K A Corey,et al.  Carbon dioxide exchange of lettuce plants under hypobaric conditions. , 1996, Advances in space research : the official journal of the Committee on Space Research.

[8]  P. Geigenberger,et al.  Response of plant metabolism to too little oxygen. , 2003, Current opinion in plant biology.

[9]  M. Drew,et al.  Mechanisms of Inhibition of Water Movement in Anaerobically Treated Roots of Zea mays L. , 1987 .

[10]  S. Biemelt,et al.  Re-Aeration following Hypoxia or Anoxia Leads to Activation of the Antioxidative Defense System in Roots of Wheat Seedlings , 1998, Plant physiology.

[11]  Ray A. Bucklin,et al.  Low Pressure Greenhouse Concepts for Mars: Atmospheric Composition , 2002 .

[12]  Michele Perchonok,et al.  Quality characteristics of the radish grown under reduced atmospheric pressure , 2008 .

[13]  F. Davies,et al.  Hypobaria and hypoxia affects growth and phytochemical contents of lettuce. , 2009 .

[14]  F. Davies,et al.  Effect of hypobaric conditions on ethylene evolution and growth of lettuce and wheat. , 2003, Journal of plant physiology.

[15]  C. Kubota,et al.  Effects of supplemental light quality on growth and phytochemicals of baby leaf lettuce , 2009 .

[16]  J. V. Bannister,et al.  The conserved residue tyrosine 34 is essential for maximal activity of iron-superoxide dismutase from Escherichia coli. , 1997, Biochemistry.

[17]  F. Davies,et al.  Separating the effects of hypobaria and hypoxia on lettuce: growth and gas exchange. , 2007, Physiologia plantarum.

[18]  R. Bucklin,et al.  The effects of CO2 on growth and transpiration of radish (Raphanus sativus) in hypobaria , 2010 .

[19]  K. Kurata,et al.  Short-term and long-term effects of low total pressure on gas exchange rates of spinach. , 2003, Advances in space research : the official journal of the Committee on Space Research.

[20]  A. Pradet,et al.  Critical oxygen pressure for growth and respiration of excised and intact roots. , 1984, Plant physiology.

[21]  E. Goto,et al.  Growth and Development of Higher Plants Under Hypobaric Conditions , 2002 .

[22]  Y. Xiao,et al.  Influence of atmospheric oxygen on leaf structure and starch deposition in Arabidopsis thaliana. , 2001, Plant, cell & environment.

[23]  W. Ai,et al.  Effects of long-term low atmospheric pressure on gas exchange and growth of lettuce , 2010 .