Investigation of the Global Changes in Photosynthetic Electron Transport in Plants Grown Under Different Light Levels.

To reveal the global regulation of photosynthetic electron transport (PET) in shade plants, the changes in chlorophyll fluorescence induction kinetics (CFI) curves and proteomics were investigated using varieties. There was a significant difference in CFI curves between 'Fire Island' and other varieties (such as 'Sum and Substance') grown under weak light. Weak light induced the appearance of the W phase of CFI curves in the two varieties, which was consistent with a clear decrease in the oxygen-evolving complex and a large upregulation of photosystem (PS) II proteins.

Sunflower Leaf Structure Affects Chlorophyll Fluorescence Induction Kinetics In Vivo.

Chlorophyll fluorescence induction kinetics (CFI) is an important tool that reflects the photosynthetic function of leaves, but it remains unclear whether it is affected by leaf structure. Therefore, in this study, the leaf structure and CFI curves of sunflower and sorghum seedlings were analyzed. Results revealed that there was a significant difference between the structures of palisade and spongy tissues in sunflower leaves.

A Changing Light Environment Induces Significant Lateral CO Diffusion within Maize Leaves.

A leaf structure with high porosity is beneficial for lateral CO diffusion inside the leaves. However, the leaf structure of maize is compact, and it has long been considered that lateral CO diffusion is restricted. Moreover, lateral CO diffusion is closely related to CO pressure differences (ΔCO).

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.

Photosynthetic acclimation during low-light-induced leaf senescence in post-anthesis maize plants.

Low light conditions not only induce leaf senescence, but also photosynthetic acclimation. This study aimed to determine whether plants exhibit photosynthetic acclimation during low-light-induced leaf senescence. The influences of shading on leaf senescence and photosynthetic acclimation were explored in post-anthesis maize plants.

Local weak light induces the improvement of photosynthesis in adjacent illuminated leaves in maize seedlings.

To copy with highly heterogeneous light environment, plants can regulate photosynthesis locally and systemically, thus, maximizing the photosynthesis of individual plants. Therefore, we speculated that local weak light may induce the improvement of photosynthesis in adjacent illuminated leaves in plants. In order to test this hypothesis, maize seedlings were partially shaded, and gas exchange, chlorophyll a fluorescence and biochemical analysis were carefully assessed.

Stomatal Sensitivity to Vapor Pressure Deficit and the Loss of Hydraulic Conductivity Are Coordinated in , a Desert Phreatophyte Species.

There are considerable variations in the percentage loss of hydraulic conductivity () at mid-day minimum water potential among and within species, but the underpinning mechanism(s) are poorly understood. This study tested the hypothesis that plants can regulate leaf specific hydraulic conductance ( ) precise control over under variable Δ (water potential differential between soil and leaf) conditions to maintain the constant (: the sensitivity of stomatal conductance to ; : reference stomatal conductance at 1.0 kPa ), where is vapor pressure deficit.

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.

Ion micro-distribution in varying aged leaves in salt-treated cucumber seedlings.

Na distribution is one of the most important strategies for plant resistance to salt stress. The way of Na compartmentation in different aged leaves has been controversial, especially at the cell and sub-cellular level. The roles that Na and K/Na play the key role in photosynthesis need to be further verified.

Variability of mesophyll conductance and its relationship with water use efficiency in cotton leaves under drought pretreatment.

Drought slows net photosynthetic rate (AN) but increases water use efficiency (WUE). Farmers give an artificial drought pretreatment to some crops in the early growth stage and find that yield increases accompanying with the improvement of WUE. We conducted well-watered, non-drought, mild drought and moderate drought pretreatments of potted cotton cultivars.

Effects of stomatal development on stomatal conductance and on stomatal limitation of photosynthesis in Syringa oblata and Euonymus japonicus Thunb.

During leaf development, the increase in stomatal conductance cannot meet photosynthetic demand for CO2, thus leading to stomatal limitation of photosynthesis (Ls). Considering the crucial influences of stomatal development on stomatal conductance, we speculated whether stomatal development limits photosynthesis to some extent. To test this hypothesis, stomatal development, stomatal conductance and photosynthesis were carefully studied in both Syringa oblata (normal greening species) and Euonymus japonicus Thunb (delayed greening species).

Effects of mutual shading on the regulation of photosynthesis in field-grown sorghum.

In the field, close planting inevitably causes mutual shading and depression of leaf photosynthesis. To clarify the regulative mechanisms of photosynthesis under these conditions, the effects of planting density on leaf structure, gas exchange and proteomics were carefully studied in field-grown sorghum. In the absence of mineral deficiency, (1) close planting induced a significant decrease in light intensity within populations, which further resulted in much lower stomatal density and other anatomical characteristics associated with shaded leaves; (2) sorghum grown at high planting density had a lower net photosynthetic rate and stomatal conductance than those grown at low planting density; (3) approximately 62 protein spots changed their expression levels under the high planting density conditions, and 22 proteins associated with photosynthesis were identified by mass spectrometry.

Systemic regulation of leaf anatomical structure, photosynthetic performance, and high-light tolerance in sorghum.

Leaf anatomy of C3 plants is mainly regulated by a systemic irradiance signal. Since the anatomical features of C4 plants are different from that of C3 plants, we investigated whether the systemic irradiance signal regulates leaf anatomical structure and photosynthetic performance in sorghum (Sorghum bicolor), a C4 plant. Compared with growth under ambient conditions (A), no significant changes in anatomical structure were observed in newly developed leaves by shading young leaves alone (YS).

Water translocation between ramets of strawberry during soil drying and its effects on photosynthetic performance.

To explore the mechanisms underlying water regulation in clonal plants and its effects on carbon assimilation under water stress, we studied the responses of water status, gas exchange and abscisic acid (ABA) contents to water stress in leaves of pairs of strawberry ramets that consist of mother and daughter ramets. There was a greater decrease in photosynthetic rates (P(n)) and stomatal conductance (G(s)) in the disconnected mother ramets than the connected mother ramets upon exposure to water stress, indicating that water stress in mother ramets was alleviated by water translocation from the well-watered daughter ramets. Conversely, the connected mother ramets displayed enhanced symptoms of water stress when the connected daughter ramets were exposed to water deficit.

Inhibition of Ageratina adenophora on spore germination and gametophyte development of Macrothelypteris torresiana.

Allelopathy of Ageratina adenophora plays an important role in its invasion. However, we have little knowledge of its allelpathic effects on ferns. In Petri dish bioassays, the inhibitory potential of aqueous leachates from roots, stems and leaves of A.

Effects of iron deficiency on photosynthesis and photosystem II function in soybean leaf.

Gas exchange and chlorophyll a fluorescence in soybean plants were investigated to explore the effects of iron deficiency on photosynthesis and photosystem II function in vivo. Iron deficiency induced a drastic decrease in net photosynthesis (Pn). Compared with normal plants, the maximal quantum yield of PSII photochemistry (psipo) in iron-deficient plants was only slightly lower; whereas, the efficiency with which a trapped exciton can move an electron into the electron transport chain further than QA-(Psio) and quantum yield of electron transport beyond QA (psiEo) were significantly depressed.

[Photosynthetic characteristics and photoprotective mechanisms during leaf development of soybean plants grown in the field].

Gas exchange, chlorophyll a fluorescence and HPLC analysis were used to explore photosynthesis and dissipation of excited energy in soybean leaves from emergence to full development. During leaf development, both photosynthetic rate and stomata conductance increased gradually, whereas the increase in stomata conductance significantly lagged behind that of photosynthetic rate. Considering stomatal limiting value, it can be easily deduced that photosynthesis was considerably limited by low stomatal conductance during leaf development.