This study monitored changes in chlorophyll fluorescence (CF), growth parameters, soil moisture content, phytochemical content (proline, ascorbic acid, chlorophyll, total phenol (TPC), and flavonoid (TFC)), antioxidant activities 12-day-old lettuce (Lactuca sativa L.) seedlings grown under drought stress (no irrigation) control (well irrigated) treatments controlled conditions for eight days. M...

NPQ (non-photochemical quenching) is a fundamental photosynthetic mechanism by which plants protect themselves against excess excitation energy and the resulting photodamage. A discussed molecular mechanism of the so-called feedback de-excitation component (qE) of NPQ involves the formation of a quenching complex. Recently, we have studied the influence of formation of a zeaxanthin-chlorophyll ...

Monogalactosyldiacylglycerol (MGDG) is the most abundant lipid on earth and constitutes about 50% of polar lipids in thylakoid membrane higher plants. MGDG synthase (MGD) key enzyme responsible for synthesis However, so far, function MGD gene plant stress responses still unknown, especially crop In this study, performances wild-type rice (Oryza sativa L. Nipponbare), OsMGD overexpression, RNA i...

With the continuous improvement of mechanization level and development new crop varieties, optimal strip width for intercropping crops is important. In this study, field experiments were conducted to analyze effects different row spacings planting patterns on photosynthesis, chlorophyll fluorescence, related enzyme activities maize ear leaves in a maize–soybean system using two (wide–narrow row...

We propose a rate process model for describing photochemical damage to retinal cells by short wavelength laser exposures. The rate equation for photochemical damage contains a positive rate that is temperature independent, and a negative (quenching) rate that is temperature dependent. Using the traditional Arrhenius integral to describe thermal damage, we derive damage threshold doses for both ...

To determine the mechanism of carotenoid-sensitized non-photochemical quenching in cyanobacteria, the kinetics of blue-light-induced quenching and fluorescence spectra were studied in the wild type and mutants of Synechocystis sp. PCC 6803 grown with or without iron. The blue-light-induced quenching was observed in the wild type as well as in mutants lacking PS II or IsiA confirming that neithe...

Photochemical quenching, nonphotochemical quenching, and yield of photosystem II were measured on seedlings of full-sibling, open-, and self-pollinated slash pine (Pinus elliottii Engelm. var. elliottii) families. Our results reveal that genetic variation in photochemical quenching and yield of photosystem II exists within this species. The pattern of variation found in these traits is consiste...

Hordeum jubatum L. is a potential ornamental grass species. Spermidine (Spd) plays regulatory role in plant stress. This study measured seedling growth, photosynthesis, chlorophyll fluorescence, osmotic substance contents, and antioxidant enzyme activities H. seedlings pretreated with Spd (0–1.5 mM at 0.5 intervals) drought treatments simulating natural water loss. The results indicated that th...

KO E H N, A.C. (Alabama A&M University, Normal, AL 35762) AND R.L. DOUDRICK (Southern Institute of Forest Genetics, Saucier, MS 39574). Diurnal patterns of chlorophyll fluorescence and CO, fixation in orchard grown Torreya ta.n’jdiu (Am.). Bull. Torrey Bot. Sot. 126:93398. 1999.-Chlorophyll fluorescence and CO, fixation measurements were taken on sunny days in October, 1996, on three Torreyu ta...