The effect of sulphite on chlorophyll fluorescence and sucrose metabolism in poplar leaves

Abstract

Sulphite at concentrations from 0.5 to 5.0 mM was supplied to illuminated, detached poplar (Populus deltoides Bartr. ex Marsh) leaves via the transpiration stream. Chlorophyll a fluorescence parameters, the contents of fructose-2,6-bisphosphate (Fru2,6BP) and starch, and extractable specific activity of sucrose-phosphate synthase (SPS), sucrose synthase (SuSy), acid invertase (AI), neutral invertase (NI), ATP-dependent fructose-6-phosphate 1-phosphotransferase (PFK) and pyrophosphate-dependent fructose-6-phosphate 1-phosphotransferase (PFP) were measured. Chlorophyll fluorescence parameters appeared to be unaffected by sulphite. Application of > 1.0 mM sulphite led to an increase in the content of Fru2,6BP and starch. There was also a decline in the activity of SPS, NI and PFK. On the other hand, the influence of sulphite on the activity of AI and PFP was negligible. Specific activity of SuSy was inhibited by 1.0 and 2.5 mM but activated by 5.0 mM of sulphite. On the basis of the results obtained in the present study, we postulate that sulphite at concentrations > 1.0 mM inhibits primarily sucrose synthesis, favours starch accumulation and has an indirect effect on the sucrolytic activities in poplar leaves.List of abbreviations: AI, acid invertase; Fv/Fm, m a x i m u m photochemical efficiency of PS II; Fv/Fo, efficiency of the photochemistry of PS II; F r u l , 6 B P a s e , f r u c t o s e -1 , 6 -b i s p h o s p h a t a s e ; Fru2,6BP, fructose-2,6-bisphosphate; LPI, leaf plastochron index; NI, neutral invertase; PEG, polyethylene glycol; PFK, ATP-dependent fructose-6-phosphate 1-phosphotransferase; PFP, pyrophosphate-dependent fructose-6-phosphate 1-phosphotransferase; PVP, polyvinylpyrrolidone; SPS, sucrose-phosphate synthase; SuSy, sucrose synthase.

The Growth Parameters of Some Species of Lawn Grasses Under Conditions of Complex Fluoride and Sulfite Soil Pollution

“…Кінцевим накопичувачем забруднювачів, що потрапляють у навколишнє середовище, є ґрунт, на який осаджуються газоподібні забруднювачі й аерозолі з атмосфери, потрапляють тверді відходи промисловості. Забруднення ґрунту чинить значний негативний вплив на фізіолого-біохімічні процеси [11,15,17,18,[22][23][24][25]28], ростові параметри [3,12,19] та продуктивність [21] рослин. Разом з тим, рослини відіграють важливу роль в оптимізації навколишнього середовища, будучи природним фільтром.…”