No abstract

Lonicera confusa was a medical plant which could adapt to the Ca-rich environment in the karst area of China. The photosynthesis, relative chlorophyll content,differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) of L. confusa that cultivated in calcareous and sandstone soils were investigated. The results showed that the relative chlorophyll content and net photosynthesis rate of L. confusa in calcareous soil are much higher than that planted in sandstone soil, the higher content of calcium might play a role in keeping the chloroplast from harm and showed higher photosynthesis rate. The transpiration and stomata conductance were decreased in calcareous soil, which might result from the closure of stomata. The GeneFishing and proteomic results showed that the expression of DEGs and DEPs were critical for photosynthesis and stomata closure, such as RuBisCO, photosynthetic electron transfer c and malate dehydrogenase varied in the leaves of L. confusa that cultivated in different soils. These DEGs or DEPs were further found to be directly or indirectly regulated by calcium sensor proteins. This study enriched our knowledge of the molecular mechanism of high net photosynthesis rate and lower transpiration of L. confusa that cultivated in the calcareous soil in some degree.

Plants have several strategies to adapt to different environments. Lonicera confusa is a typical species in karst calcium (Ca)-rich environments; to adapt to the Ca-rich environment, it excretes calcium by leaf stoma. In the present study, the calcium-excretion process of L. confusa was investigated by scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX). We compared the different types of Ca crystals by self-assembly of secreted products with point and line-by-line scanning. Ca crystals are formed after Ca salt is excreted by stoma of L. confusa in the karst Ca-rich environment. Ca salt could self-assemble 3 types of crystals, prisms, ball and crystal sand. Crystals have a large amount of Ca, and sulfur (S) and other elements, which are present in certain ratio. The crystal nucleus protein is rich in S element, which is beneficial for biomineralization of Ca-related crystal and others. EDX could be effectively used for microprobe analysis of plant leaves and identifying plant-excreted products.

Two-dimensional polyacrylamide gel electrophoresis has been widely applied in proteomic researches. The approach can analyze dynamic changes of proteomics of biological samples under different conditions to identify specific proteins and genes. The two-dimensional gel systems for rice, Arabidopsis, and other species have been established. The purpose of this research was to establish a suitable system for B. napus to analyze proteomics. Rapeseed variety of 08127 was used in the experiment, the proteins were obtained by the trichloroacetic extraction method with pH 4-7 gel brands under the improved IEF procedure, showing a clean two-dimensional electrophoresis map. Therefore, a proper system for B. napus was formed. Then the system was validated by using the young seedlings, leaves and stems from other varieties, and the same results as those from variety 08127 were obtained. The proteomics profiling of seedlings in different ages of B. napus was analyzed by using the previous established protocol, we found 20 up-regulated and 51 down-regulated proteins with more than two times changes in 30 days old B. napus stems compared with in 15 days old B. napus stems and some of the different protein spots were successfully identified. The system established in this study is useful for B. napus proteomic research in the future.