Anthocyanin metabolism in Nelumbo: translational and post-translational regulation control transcription.

BACKGROUND: Lotus (Nelumbo Adans.) is used as an herbal medicine and the flowers are a source of natural flavonoids. 'Da Sajin', which was firstly found in the plateau area, is a natural mutant in flower color with red streamers dyeing around white petals. RESULTS: The LC-MS-MS results showed that eight anthocyanin compounds, including cyanidin 3-O-glucoside, cyanidin 3-O-galactoside, malvidin 3-O-galactoside, and malvidin 3-O-glucoside, were differentially enriched in red-pigmented tissues of the petals, whereas most of these metabolites were undetected in white tissues of the petals. Transcriptome profiling indicated that the relative high expression levels of structural genes, such as NnPAL, NnF3H, and NnANS, was inconsistent with the low anthocyanin concentration in white tissues. Members of the NnMYB and NnbHLH transcription factor families were presumed to play a role in the metabolic flux in the anthocyanin and proanthocyanidin biosynthetic pathway. The expression model of translational initiation factor, ribosomal proteins and SKP1-CUL1-F-box protein complex related genes suggested an important role for translational and post-translational network in anthocyanin biosynthesis. In addition, pathway analysis indicated that light reaction or photo destruction might be an important external cause for floral color determination in lotus. CONCLUSIONS: In this study, it is supposed that the natural lotus mutant 'Da Sajin' may have originated from a red-flowered ancestor. Partial loss of anthocyanin pigments in petals may result from metabolic disorder caused by light destruction. This disorder is mainly regulated at post translation and translation level, resulting in a non-inherited phenotype. These results contribute to an improved understanding of anthocyanin metabolism in lotus, and indicate that the translational and post-translational regulatory network determines the metabolic flux of anthocyanins and proanthocyanidins under specific environmental conditions.

Phytoremediation performance of three traditional ornamental hydrophytes and the structure of their rhizosphere microorganism populations.

The use of phytoremediation technology in urban and rural landscapes can permit both aesthetic and water purification functions to be achieved sustainably. Here, the ability of three ornamental aquatic plant species (Lythrum salicaria L., Sagittaria trifolia L., and Typha orientalis C. Presl) to remove nutrients from simulated contaminated water over 35 days and the structure of their rhizosphere microorganism populations were evaluated to examine their potential to be used for landscape phytoremediation as well as determine the mechanism of nutrient removal. L. salicaria had the highest nutrient removal ability (86.91-96.96% removal efficiency of total nitrogen and 46.04-66.70% removal efficiency of total phosphorus). The population structure of rhizosphere microorganisms was mainly affected by plant species and not the nutrient level of the water body according to principal coordinates analysis and non-metric multi-dimensional scaling. Betaproteobacteriales and Chitinophagales were highly correlated with the content of nutrients in water according to redundancy analysis. The accumulation of the two orders by L. salicaria and higher biomass might explain the stronger removal ability of L. salicaria. The findings of this study indicate that these plants could enhance urban and rural water landscape design; our results also shed new light on the mechanism of phytoremediation by rhizosphere microorganisms.

Trends and Causes of Raw Water Quality Indicators in the Five Most Famous Lakes of Jiangsu Province, China.

Due to pollutants from industrial and agricultural activities, the lakes in China are faced with ecological and environmental problems. The five most famous lakes of Jiangsu Province, Taihu Lake, Gehu Lake, Gaobaoshaobo Lake, Hongze Lake, and Luoma Lake, have long-term fixed monitoring points for water body-related indicators. Over a five-year period, the monitoring showed that Gehu Lake had the highest average total nitrogen (TN) and total phosphorus (TP) concentrations among all lakes which were close to the Grade V critical value of the China's Environmental Quality Standards for Surface Water (CEQSW). The NH3-N concentrations in all lakes were Grade IV according to the China's Water Quality Standard for Drinking Water Sources (CWQSDWS) and Grade II according to the CEQSW. In addition, although TP concentrations in Taihu Lake did not exceed Grade V in the CEQSW, TP removal was the main factor controlling eutrophication. It was also found that the petroleum concentrations in all lakes were lower than the Grade I according to the CEQSW. Despite this relatively low petroleum pollution, the concentration of petroleum was negatively correlated with the phytoplankton densities in all lakes. This indicated that phytoplankton density was very sensitive to petroleum concentration. For heavy metals, the concentrations of Pb, Cu, As, and Cd in all lakes were significantly lower than Grade I (CEQSW) from 2013 to 2017. However, the accumulated heavy metals in sediments will remain an important pollution source affecting water quality and aquatic products in the future. The comprehensive pollution index analysis showed that the five lakes were often moderately polluted, indicating that the protection of lake resources in China should not be relaxed for a long time in the future.

Characterization and phylogenetic analysis of the complete chloroplast genome of Ilex rotunda, traditional Chinese medicine plant.

Ilex rotunda is a traditional Chinese medicine plant. In this study, we characterized the complete chloroplast (cp) genome sequence of I. rotunda to investigate its phylogenetic relationship. The cp genome of I. rotunda was 157,743 bp in length with 37.62% overall GC content, including a large single-copy (LSC) region of 87,060bp, a small single-copy (SSC) region of 18,432 bp, which were separated by a pair of inverted repeats (IRS) of 26,121 bp. The cp genome contained 133 genes, including 88 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis based on whole cp genome sequences showed that I. rotunda is closely related to I. pubescens and I. polyneura.

A New Green Model for the Bioremediation and Resource Utilization of Livestock Wastewater.

The rapid growth of the livestock and poultry industries has resulted in the production of a large amount of wastewater, and the treatment of this wastewater requires sustainable and environmentally friendly approaches such as phytoremediation. A substrate-free floating wetland planted with water dropwort (Oenanthe javanica), a common vegetable in Southeast China, was constructed to purify a lagoon with anaerobically and aerobically treated swine wastewater in Suqian, China. The average removal rates of total nitrogen, ammonium nitrogen, nitrite nitrogen, and chemical oxygen demand were 79.96%, 95.04%, 86.14%, and 59.91%, respectively, after 40 days of treatment. A total of 98.18 g∙m-2 nitrogen and 19.84 g∙m-2 phosphorus were absorbed into plants per harvest through the rapid growth of water dropwort biomass, and the nitrogen accumulation ability was similar to that observed of other plants, such as water hyacinth. In addition, the edible part of water dropwort was shown to comply with the Chinese National Food Sanitation Standards and be safe for human consumption. Its low soluble sugar content also makes it a suitable addition to the daily diet. Overall, substrate-free floating constructed wetlands planted with water dropwort could be more widely used for livestock wastewater purification and could be integrated with plant-livestock production in China because of its high removal efficiency and recycling utilization of water dropwort biomass.

Characterization of the Mitochondrial Genome of a Wheat AL-Type Male Sterility Line and the Candidate CMS Gene.

Heterosis utilization is very important in hybrid seed production. An AL-type cytoplasmic male sterile (CMS) line has been used in wheat-hybrid seed production, but its sterility mechanism has not been explored. In the present study, we sequenced and verified the candidate CMS gene in the AL-type sterile line (AL18A) and its maintainer line (AL18B). In the late uni-nucleate stage, the tapetum cells of AL18A showed delayed programmed cell death (PCD) and termination of microspore at the bi-nucleate stage. As compared to AL18B, the AL18A line produced 100% aborted pollens. The mitochondrial genomes of AL18A and AL18B were sequenced using the next generation sequencing such as Hiseq and PacBio. It was found that the mitochondrial genome of AL18A had 99% similarity with that of Triticum timopheevii, AL18B was identical to that of Triticum aestivum cv. Chinese Yumai. Based on transmembrane structure prediction, 12 orfs were selected as candidate CMS genes, including a previously suggested orf256. Only the lines harboring orf279 showed sterility in the transgenic Arabidopsis system, indicating that orf279 is the CMS gene in the AL-type wheat CMS lines. These results provide a theoretical basis and data support to further analyze the mechanism of AL-type cytoplasmic male sterility in wheat.