Developing Phloem delta C-13 and Sugar Composition as Indicators of Water Deficit in Lupinus angustifolius

作者：Merchant Andrew^*

来源：Hortscience, 2012, 47(6): 691-696.

• legumes
• phloem
• isotope
• pinitol
• carbohydrates
• water deficit water use
• carbon

The use of naturally occurring carbon isotope ratios (expressed as delta C-13) obtained from phloem sap offers considerable promise for evaluations of short-term physiological status of plants. We investigate the suitability of delta C-13 among carbon pools isolated from both leaves and phloem sap as surrogate measures of plant gas exchange in Lupinus angustifolius L. We also investigate the use of phloem osmotic potential (psi(S)), and metabolite concentrations as surrogate measures of delta C-13. Phloem sap carbon bled from the distal tip of the fruit offers considerably improved correlations between delta C-13 and plant gas exchange compared with delta C-13 of carbon pools obtained from extractions of excised phloem tissue and leaf soluble carbon. The concentration of phloem sugars and sugar alcohols correlates strongly with measures of phloem delta C-13 but not with phloem psi(S). We discuss these results in the context of developing fast, reliable, in-field tools for the assessment of plant physiological status.

• 出版日期2012-6