کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2055783 1543902 2015 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
What is the potential for dark CO2 fixation in the facultative crassulacean acid metabolism species Talinum triangulare?
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم زراعت و اصلاح نباتات
پیش نمایش صفحه اول مقاله
What is the potential for dark CO2 fixation in the facultative crassulacean acid metabolism species Talinum triangulare?
چکیده انگلیسی

In obligate Crassulacean acid metabolism (CAM) plants, dark CO2 fixation is almost the sole route of CO2 fixation and, under drought, continues for long periods. In contrast, in plants of the facultative CAM species Talinum triangulare under experimental drought, dark CO2 fixation provides a small proportion of the daily assimilation observed in watered plants and occurs only for a few days, after which almost nil CO2 fixation is observed. Under field conditions, with a practically unlimited substrate volume, drought-induced CAM might operate for a longer period and make a higher contribution to daily CO2 fixation. Greenhouse-grown plants of T. triangulare were subjected to low and nearly constant soil water content; the operation of CAM was assessed through the measurement of nocturnal proton accumulation and dark CO2 fixation. Dark CO2 fixation appeared 19 d after the onset of drought; its contribution during three months of experiment to daily CO2 assimilation ranged from 0.5 to 30.7% with a mean of 13.5%. Twenty days after the beginning of treatment, nocturnal proton accumulation increased six times and remained high for over three months. In spite of low soil water content, leaves did not engage in dark CO2 fixation all the time but dark CO2 fixation was large enough to produce an increase in relative 13C composition of mature leaves compared to watered plants but not to the value in short-term drought experiments. Leaf anatomical characteristics may guarantee the achievement of higher rates of dark CO2 fixation but results evidence the occurrence of a limit to the expression of CAM that remains to be determined.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Plant Physiology - Volume 174, 1 February 2015, Pages 55–61
نویسندگان
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