No abstract

Calcium (Ca) is an important nutrient element for plant growth and development. Nevertheless, excessive Ca restricts plant communities in Carich environments. Lonicera confusa DC. is one species adapted to Ca-rich environments in the karst area of southwest China; however, the anatomical mechanism that allows these plants to respond to a Ca-rich environment remains unclear. L. confusa was cultivated in two types of soil with controlled Ca levels. The ultrastructure of leaves at different developmental stages was observed, and their Ca contents analyzed by laser scanning confocal microscope and energy-dispersive X-ray spectroscopy. There was no significant difference in leaves between the two experimental groups at very early stages of development. The glands of leaves growing in Carich soil became saturated and showed a steady increase of Ca content in the following stages. The Ca level in leaf trichomes also increased steadily, compared with those from Ca-poor soil. When the leaves matured, Ca salts were excreted via stomata of L. confusa from Ca-rich soil. L. confusa had a special anatomical mechanism of responding to Ca-rich environments by excreting Ca salts via stomata, and storing Ca 2+ in leaf glands and trichomes.

The effects of calcium on respiratory and nitrogen metabolism of apple roots (Malus baccata Borkh.) exposed to temperature stress (5°C ~ 20°C ~ 0°C) were investigated. Seedlings were treated with distilled water (control), calcium chloride (CaCl2) or calmodulin antagonist trifluoperazine (TFP) before temperature stress. Temperature was increased from 5°C to 20°C (1°C h ). Temperature stress decreased root vitality and increased root malondialdehyde (MDA) concentration, the effect of which was exacerbated by TFP treatment. Treatment with CaCl2 improved root vitality and decreased root MDA concentration. At 20°C, exogenous CaCl2 alleviated the negative effects of temperature stress on the total respiration rate by enhancing the activity of tricarboxylic acid cycle (TCA). Activities of key enzyme in nitrogen metabolism were strongly inhibited by temperature stress. Exogenous CaCl2 significantly increased key enzyme activities of nitrogen metabolism compared to the control. However, the TFP treatment markedly reduced the activity of glutamate synthase (GOGAT) at 20°C and noticeably inhibited glutamate dehydrogenase (GDH) activity during the entire temperature stress period. The data showed that the Ca 2+ -calmodulin (Ca 2+ -CaM) signal system was involved in increase of GOGAT and GDH activity that occurred with an increase in temperature, and played a role in the increase in the total respiration rate and GDH activity which occurred with a decrease in temperature. Cultural practices that improve plant calcium (Ca) status in the early spring may mitigate damage induced by temperature stress.

In this paper, we present a set of best practices for workflow design and implementation for numerical weather prediction models and meteorological data service, which have been in operation in China Meteorological Administration (CMA) for years and have been proven effective in reliably managing the complexities of large-scale meteorological related workflows. Based on the previous work on the platforms, we argue that a minimum set of guidelines including workflow scheme, module design, implementation standards and maintenance consideration during the whole establishment of the platform are highly recommended, serving to reduce the need for future maintenance and adjustment. A significant gain in performance can be achieved through the workflow-based projects. We believe that a good workflow system plays an important role in the weather forecast service, providing a useful tool for monitoring the whole process, fixing the errors, repairing a workflow, or redesigning an equivalent workflow pattern with new components.