Growth temperature alters temperature dependence of the photosynthetic rate (temperature acclimation). In many species, the optimal temperature that maximizes the photosynthetic rate increases with increasing growth temperature. In this minireview, mechanisms involved in changes in the photosynthesis-temperature curve are discussed. Based on the biochemical model of photosynthesis, change in the photosynthesis-temperature curve is attributable to four factors: intercellular CO2 concentration, activation energy of the maximum rate of RuBP (ribulose-1,5-bisphosphate) carboxylation (Vc max), activation energy of the rate of RuBP regeneration (Jmax), and the ratio of Jmax to Vc max. In the survey, every species increased the activation energy of Vc max with increasing growth temperature. Other factors changed with growth temperature, but their responses were different among species. Among these factors, activation energy of Vc max may be the most important for the shift of optimal temperature of photosynthesis at ambient CO2 concentrations. Physiological and biochemical causes for the change in these parameters are discussed.

Our results reveal that nitrogen distribution is mainly driven by the vertical light gradient but other factors such as LAI also have significant effects. Our equations contribute to an improvement in the projection of plant productivity and cycling of carbon and nitrogen in terrestrial ecosystems.

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There was both an increase in the absolute value of the light-saturated photosynthetic rate at growth CO(2) (P(growth)) and an increase in T(opt) for P(growth) caused by elevated CO(2) in FACE conditions. Seasonal decrease in P(growth) was associated with a decrease in nitrogen content per unit leaf area (N(area)) and thus in the maximum rate of electron transport (J(max)) and the maximum rate of RuBP carboxylation (V(cmax)). At ambient CO(2), T(opt) increased with increasing growth temperature due mainly to increasing activation energy of V(cmax). At elevated CO(2), T(opt) did not show a clear seasonal trend. Temperature dependence of photosynthesis was changed by seasonal climate and plant nitrogen status, which differed between ambient and elevated CO(2).

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Lung cancer is one of the most widely recognised types of cancer and the acquisition of resistance towards chemotherapeutic drugs worsens the situation. Therefore, a site-directed, multi-targeting drug delivery system that is compliant with patients is the need of the hour. 5-Fluorouracil (5-FU), an anti-cancer chemotherapy drug, was delivered to the lung cancer cells using papain-inspired gold nanoparticles (PpGNPs) as the drug delivery system. Papain is anti-cancer by nature; hence, it rendered this anti-cancer property to the PpGNPs as well. This bio-conjugation of 5-FU and PpGNPs worked synergistically and more efficiently in combating lung cancer. The synthesis, stability, and the size of the PpGNPs, and their bio-conjugation with 5-FU (5F-PpGNPs), were confirmed by different physical techniques: for example, UV-Vis spectroscopy, TEM, DLS, and estimation of the zeta potential. The drugloading efficiency of 5-FU in 5F-PpGNPs was confirmed and validated by UV-Vis spectroscopy. The efficacy of 5F-PpGNPs (IC 50 11.7 mg/mL) against human lung cancer A549 cell line was found to have improved significantly over that of pure 5-FU (IC 50 25.6 mg/mL). However, the 5F-PpGNPs did not show any significant toxicity (even up to a fairly high concentration) towards normal mouse embryonic fibroblasts cell line (3T3-L1). The apoptotic effects, nuclear condensation, ROS generation, and the loss of mitochondrial membrane potential (DWm) of 5F-PpGNPs were analysed. The results clearly showed that conjugation with papain-inspired gold nanoparticles (5F-PpGNPs) significantly augmented the potency of 5-FU by acting synergistically. Thus, the enhanced anti-proliferating effect of 5F-PpGNPs over that of the pure drug would be an important step that will help to ARTICLE HISTORY