The Unique Existence of Chromosomal Abnormality in Polyploidy Plants

It is commonly acknowledged that chromosomal abnormality is the popular natural phenomenon especially with polyploidy plants. The unique existence in plants has actually become one of major forces for speciation and evolution. This means that plants existing chromosomal abnormality developing through sexual and asexual pathways shed light on increasing biomass, adapting ecology so these benefits are more important and worth exploring. With regard to the former, chromosomal abnormality plants lead to not only gigantic effect but also increasing phytochemical compounds. As far as ecological perspectives are concerned, this abnormality enhances biotic and abiotic tolerance to adapt to climate change. These things also answer a question why plants can commonly exist with many kinds of chromosomal abnormalities. Based on aforementioned benefits, this review provides human beings with several chances when they need in developing the food security strategies.

Predictions of biodiversity are improved by integrating trait-based competition with abiotic filtering

All organisms must simultaneously tolerate the environment and access limiting resources if they are to persist. Otherwise they go extinct. Approaches to understanding environmental tolerance and resource competition have generally been developed independently. Consequently, integrating the factors that determine abiotic tolerance with those that affect competitive interactions to model species abundances and community structure remains an unresolved challenge. This is likely the reason why current models of community assembly do not accurately predict species abundances and dynamics. Here, we introduce a new synthetic framework that models both abiotic tolerance and biotic competition by using functional traits, which are phenotypic attributes that influence organism fitness. First, our framework estimates species carrying capacities that vary along abiotic gradients based on whether the phenotype tolerates the local environment. Second, it estimates pairwise competitive interactions as a function of multidimensional trait differences between species and determines which trait combinations produce the most competitive phenotypes. We demonstrate that our combined approach more than doubles the explained variance of species covers in a wetland community compared to the model of abiotic tolerances alone. Trait-based integration of competitive interactions and abiotic filtering improves our ability to predict species abundances across space, bringing us closer to more accurate predictions of biodiversity structure in a changing world.

SpPKE1, a Multiple Stress-Responsive Gene Confers Salt Tolerance in Tomato and Tobacco

Understanding the mechanism of abiotic-tolerance and producing germplasm of abiotic tolerance are important in plant research. Wild species often show more tolerance of environmental stress factors than their cultivated counterparts. Genes from wild species show potential abilities to improve abiotic resistance in cultivated species. Here, a tomato proline-, lysine-, and glutamic-rich type gene SpPKE1 was isolated from abiotic-resistant species (Solanum pennellii LA0716) for over-expression in tomato and tobacco for salt tolerance. The protein encoded by SpPKE1 was predominantly localized in the cytoplasm in tobacco. SpPKE1 and SlPKE1 (from cultivated species S. lycopersicum cv. M82) shared 89.7% similarity in amino acid sequences and their transcripts abundance in flowers and fruits was reduced by the imposition of drought or oxidative stress and the exogenous supply of abscisic acid. The DNA of the PKE1 promoter was highly methylated in fruit and leaf, and the methylation of the coding sequence in leaf was significantly higher than that in fruit at different development stages. The over-expression of SpPKE1 under the control of a CaMV (Cauliflower Mosaic Virus) 35S promoter in transgenic tomato and tobacco plants enhanced their tolerance to salt stress. PKE1 was downregulated by abiotic stresses but enhanced the plant’s salt stress tolerance. Therefore, this gene may be involved in post-transcriptional regulation and may be an important candidate for molecular breeding of salt-tolerant plants.

Microarray analysis of different expression profiles between wild-type and transgenic rice seedlings overexpression OsDREB1BI gene

Overexpressed genes encoding the transcription factors of DREB/CBF can improve abiotic tolerance in transgenic plants. However, the mechanism of plant abiotic tolerance at the molecular level has not been clearly elucidated. In this study, the OsDREB1BI gene was introduced to Zhonghua 11, an Oryza sativa L. japonica variety. The rice plant hosting the OsDREB1BI gene showed an improved tolerance to low temperatures compared with wild-type plants. A total of 404 differentially expressed genes were detected in transgenic and wild-type rice plants by using the Affymetrix microarray system. Results showed that 180 or 224 genes were induced or suppressed, respectively. The functional classification of these differentially expressed genes indicated that such genes are involved in various metabolic pathways, including coding for stress-response-related proteins. The number of up-regulated genes (56) was greater than that of the down-regulated genes (24). Proteins with an unknown function constituted the highest proportion. The gene encoding an AP2 domaincontaining protein RAP2.8 was down-regulated in the transgenic rice plant. Many “hot” sites, where some up-regulated or down-regulated genes were clustered, were found in rice chromosomes.