Photosynthetic mechanism of maize yield under fluctuating light environments in the field.

The photosynthetic mechanism of crop yields in fluctuating light environments in the field remains controversial. To further elucidate this mechanism, we conducted field and simulation experiments using maize (Zea mays) plants. Increased planting density enhanced the light fluctuation frequency and reduced the duration of daily high light, as well as the light-saturated photosynthetic rate, biomass, and yield per plant.

[Chemical constituents from Morinda citrifolia and their inhibitory activities on proliferation of synoviocytes in vitro].

The chemical constituents from the stems and leaves of Morinda citrifolia were isolated and purified by column chromatography methods with silica gel, ODS, Sephadex LH-20 and preparative high performance liquid chromatography(HPLC). The structures of the isolated compounds were identified by physicochemical properties and spectroscopic analysis, as well as comparisons with the data reported in literature. 17 compounds were isolated from the 90% ethanol extract of the stems and leaves of M.

Prenylated coumarins from the fruits of with their potential anti-inflammatory and anti-HIV activities.

A phytochemical investigation on the fruits of led to the isolation and characterisation of a new prenylated coumarin, artoheteronin (), together with six known analogues (-). The chemical structure of was elucidated using extensive spectral methods and the known compounds (-) were identified by comparing their spectral data with those reported in the literature. All known compounds (-) were isolated from the genus for the first time.

Do rapid photosynthetic responses protect maize leaves against photoinhibition under fluctuating light?

Plants in their natural environment are often exposed to fluctuating light because of self-shading and cloud movements. As changing frequency is a key characteristic of fluctuating light, we speculated that rapid light fluctuation may induce rapid photosynthetic responses, which may protect leaves against photoinhibition. To test this hypothesis, maize seedlings were grown under fluctuating light with various frequencies (1, 10, and 100 cycles of fluctuations/10 h), and changes in growth, chlorophyll content, gas exchange, chlorophyll a fluorescence, and P700 were analyzed carefully.