A proteomic approach to analyzing responses of Arabidopsis thaliana root cells to different gravitational conditions using an agravitropic mutant, pin2 and its wild type

<p>Abstract</p> <p>Background</p> <p>Root gravitropsim has been proposed to require the coordinated, redistribution of the plant signaling molecule auxin within the root meristem, but the underlying molecular mechanisms are still unknown. PIN proteins are membrane transporters that mediate the efflux of auxin from cells. The PIN2 is important for the basipetal transport of auxin in roots and plays a critical role in the transmission of gravity signals perceived in the root cap to the root elongation zone. The loss of function <it>pin2 </it>mutant exhibits a gravity-insensitive root growth phenotype. By comparing the proteomes of wild type and the <it>pin2 </it>mutant root tips under different gravitational conditions, we hope to identify proteins involved in the gravity-related signal transduction.</p> <p>Results</p> <p>To identify novel proteins involved in the gravity signal transduction pathway we have carried out a comparative proteomic analysis of Arabidopsis <it>pin2 </it>mutant and wild type (WT) roots subjected to different gravitational conditions. These conditions included horizontal (H) and vertical (V) clinorotation, hypergravity (G) and the stationary control (S). Analysis of silver-stained two-dimensional SDS-PAGE gels revealed 28 protein spots that showed significant expression changes in altered gravity (H or G) compared to control roots (V and S). Whereas the majority of these proteins exhibited similar expression patterns in WT and <it>pin2 </it>roots, a significant number displayed different patterns of response between WT and <it>pin2 </it>roots. The latter group included 11 protein spots in the H samples and two protein spots in the G samples that exhibited an altered expression exclusively in WT but not in <it>pin2 </it>roots. One of these proteins was identified as annexin2, which was induced in the root cap columella cells under altered gravitational conditions.</p> <p>Conclusions</p> <p>The most interesting observation in this study is that distinctly different patterns of protein expression were found in WT and <it>pin</it>2 mutant roots subjected to altered gravity conditions. The data also demonstrate that PIN2 mutation not only affects the basipetal transport of auxin to the elongation zone, but also results in an altered expression of proteins in the root columella.</p

Cloning and expression trait of UDP-glucose:flavonoid 3-O-glucosyltransferase gene (UF3GT) in turnip

Anthocyanin is a class of important secondary metabolites in plants. UDP-glucose:flavonoid  3-O-glucosyltransferase (UF3GT) is a committed catalytic enzyme in the late stage of anthocyanin  biosynthesis. BrUF3GT1 and BrUF3GT2 genes were cloned by reverse transcription polymerase chain reaction  (RT-PCR) method from ‘Tsuda’ and ‘Yurugi Akamaru’ turnips. The open reading frame (ORF) of BrUF3GT1 and  BrUF3GT2 genes contained 1407 bp encoding proteins of 468 amino acids. Amino acid sequence analysis  showed that BrUF3GT1 and BrUF3GT2 had 87% identity to UF3GT of Arabidopsis thaliana, and the  glycosyltransferase protein family domain was in the amino acids sequence from 16 to 453. The nucleotide  sequence of BrUF3GT1 and BrUF3GT2 genes showed only seven nucleotide differences, and one common  deduced amino acid sequence. The northern blotting results showed that the expression of BrUF3GT1 and BrUF3GT2 genes could be induced by irradiation of ultra-violet A (UV-A), and the expression of the genes was correlated with light-exposure time. The 51.88 and 51.89 KDa proteins of BrUF3GT1 and BrUF3GT2 were  successfully purified after prokaryotic induced expression.Key words: Turnip, UDP-glucose:flavonoid 3-O-glucosyltransferase (UF3GT) gene, gene clone, sequence analysis, gene expression

Combined use of herbivore-induced plant volatiles and sex pheromones for mate location in braconid parasitoids

Herbivore-induced plant volatiles (HIPVs) are important cues for female parasitic wasps to find hosts. Here, we investigated the possibility that HIPVs may also serve parasitoids as cues to locate mates. To test this, the odour preferences of four braconid wasps – the gregarious parasitoid Cotesia glomerata (L.) and the solitary parasitoids Cotesia marginiventris (Cresson), Microplitis rufiventris Kokujev and Microplitis mediator (Haliday) – were studied in olfactometers. Each species showed attraction to pheromones but in somewhat different ways.Males of the two Cotesia species were attracted to virgin females, whereas females of M. rufiventriswere attracted to virginmales. Male and female M.mediator exhibited attraction to both sexes. Importantly, female and male wasps of all four species were strongly attracted by HIPVs, independent of mating status. In most cases, male wasps were also attracted to intact plants. The wasps preferred the combination of HIPVs and pheromones over plant odours alone, except M.mediator, which appears to mainly use HIPVs for mate location. We discuss the ecological contexts in which the combined use of pheromones and HIPVs by parasitoids can be expected. To our knowledge, this is the first study to show that braconid parasitoids use HIPVs and pheromones in combination to locate mates

Ecological vulnerability assessment based on remote sensing ecological index (RSEI): A case of Zhongxian County, Chongqing

The ecological vulnerability evaluation index was established through Normalized Difference Vegetation Index (NDVI), Wetness (WET), Normalized Difference Build-up and Soil Index (NDBSI) and Land Surface Temperature (LST) indicators, comprehensively evaluate the ecological vulnerability of Zhongxian County of Chongqing in 2002, 2009, and 2016 by Principal Components Analysis (PCA), and analyze its spatio-temporal evolution. The vulnerability areas of five levels were calculated respectively, and the overall index of ecological vulnerability was also calculated. The index of remote sensing ecological index (RSEI) and Normalized Difference Vegetation Index decreased first and then increased; the Wetness index showed an upward trend; the Normalized Difference Build-up and Soil Index index increased first and then decreased; and the Land Surface Temperature index decreased. The ecological vulnerability body index (EVBI) shows a downward trend, and the incremental changes are mainly concentrated in the negligible vulnerability areas and light vulnerability area, while the medium vulnerability, strong vulnerability and extreme vulnerability area generally show a downward trend. Furthermore, the new increment of ecological vulnerability grade area concentrates on negligible vulnerability area and light vulnerability area from 2002 to 2016. In general, the ecological vulnerability gradually shifts to low vulnerability, and the ecological environment tends to develop healthily