کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4528496 1324311 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of NaCl on photosynthesis, salt accumulation and ion compartmentation in two mangrove species, Kandelia candel and Bruguiera gymnorhiza
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم آبزیان
پیش نمایش صفحه اول مقاله
Effect of NaCl on photosynthesis, salt accumulation and ion compartmentation in two mangrove species, Kandelia candel and Bruguiera gymnorhiza
چکیده انگلیسی

In a 4-week study, we investigated the effects of increasing soil NaCl (100–400 mM) on photosynthesis, salt uptake and transport, and intracellular compartmentation of Na+ and Cl− in 1-year-old seedlings of Kandelia candel (L.) Druce and Bruguiera gymnorhiza (L.) Savigny. Increasing NaCl stress significantly elevated Na+ and Cl− in root and shoot tissues (stem + leaf) of both species, but B. gymnorhiza showed a rapid Na+ accumulation upon the initiation of salt stress and leaves contained 90% more Na+ and 40% more Cl− than K. candel at the end of experiment. Net photosynthetic rate (Pn) declined with increasing salinity, and the most marked reduction occurred after exposure of mangrove seedlings to a severe salinity, 400 mM NaCl. However, the inhibitory effects of severe stress varied with species: Pn decreased by 80% in K. candel whereas in B. gymnorhiza the decline was 60%. The quantum yield (AQY) and carboxylation efficiency (CE) response to severe salinity showed a trend similar to Pn, in which a lesser reduction of AQY and CE was observed in B. gymnorhiza (33–35%), as compared to K. candel (43–52%). X-ray microanalysis of leaf mesophyll cells showed evidence of distinct vacuolar compartmentation of Na+ in K. candel but Cl− in B. gymnorhiza after seedlings were subjected to 100 mM NaCl for 7 d. Moreover, Na+ within cell wall, cytoplasm, vacuole and chloroplast remained 23–72% lower in stressed B. gymnorhiza as compared to K. candel. In conclusion, B. gymnorhiza exhibited effective salt exclusion from chloroplasts although increasing salt stress caused a rapid and higher build up of Na+ and Cl− in the leaves. We suggest that the salt-induced Pn reduction in the two mangrove species is correlated with the ability to exclude Na+ and Cl− from the chloroplast, rather than with the bulk leaf salt concentration.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Aquatic Botany - Volume 88, Issue 4, May 2008, Pages 303–310
نویسندگان
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