RESUMEN
Woody plants play a vital role in global ecosystems and serve as valuable resources for various industries and human needs. While many woody plant genomes have been fully sequenced, gene function research and biotechnological breeding advances have lagged behind. As a result, only a limited number of genes have been elucidated, making it difficult to use newer tools such as CRISPR-Cas9 for biotechnological breeding purposes. The use of Agrobacterium rhizogenes as a transformative tool in plant biotechnology has received considerable attention in recent years, particularly in the research field on woody plants. Over the past three decades, numerous woody plants have been effectively transformed using A. rhizogenes-mediated techniques. Some of these transformed plants have successfully regenerated. Recent research on A. rhizogenes-mediated transformation of woody plants has demonstrated its potential for various applications, including gene function analysis, gene expression profiling, gene interaction studies, and gene regulation analysis. The introduction of the Ri plasmid has resulted in the emergence of several Ri phenotypes, such as compact plant types, which can be exploited for Ri breeding purposes. This review paper presents recent advances in A. rhizogenes-mediated basic research and Ri breeding in woody plants. This study highlights various aspects of A. rhizogenes-mediated transformation, its multiple applications in gene function analysis, and the potential of Ri lines as valuable breeding materials.
RESUMEN
Winterberry (Ilex verticillata (L.) A. Gray) is a recently introduced ornamental tree species in China that has not been closely investigated for its drought resistance. In this study, we used two-year-old cuttings from I. verticillata (L.) A. Gray and two representative varieties derived from it, I. verticillata 'Oosterwijk' and I. verticillata 'Jim Dandy', as materials to investigate how this plant responds to drought stress and whether exogenous spermidine (SPD) can alleviate the negative effects caused by drought stress. The results showed that as the degree of drought stress increased, the leaves of winterberry seedlings became chlorotic, and their edges became dry. Similarly, the relative water content, specific leaf weight, chlorophyll content, leaf nitrogen content, net photosynthetic rate, stomatal conductance and transpiration rate were significantly reduced, whereas the content of malondialdehyde continuously increased with the degree of drought stress. The activities of superoxide dismutase, peroxidase, and catalase increased under moderate drought stress and then decreased under severe drought stress. The levels of soluble sugar and abscisic acid continued to increase, while those of auxin and gibberellic acid decreased. When compared with individual drought stress, an increase in the amount of external SPD clearly alleviated the effect of drought stress on winterberry seedlings. The combined phenotypes and physiological indices of the winterberry leaves under drought stress conditions revealed that the drought resistance of the native species was significantly higher than its two varieties. This finding serves as an important theoretical foundation for the popularization and application of I. verticillata (L.) A. Gray and the two varieties.
RESUMEN
In order to clarify the eco-environmental quality and its evolution characteristics of Keluke Lake basin, we selected 15 factors of physical geography, meteorology, land use/cover and social economy using comprehensive investigation, remote sensing interpretation and inversion, statistical analysis and other technical means, based on the relevant theories of environmental ecology. We used factor analysis and entropy method to calculate the index weight, constructed watershed soil quality model and ecological environment quality diagnosis model, and analyzed the changes of soil and eco-environmental quality in the Keluke Lake basin in 2000, 2005, 2010 and 2015. The results showed that the average eco-environmental quality in four periods was 21, 47, 54, and 72, showing a stable upward trend. The eco-environmental quality level changed from poor to good, while soil quality was at the middle level. Spatially, the eco-environmental quality of the northern mountainous area, the downstream wetland and the surrounding area of the river improved significantly. The change of eco-environmental quality was a result of human activities and natural factors. Soil quality and lake area were key factors indicating the eco-environment of the Keluke Lake basin. The minimum ecological water demand of the Keluke Lake was the basic guarantee to maintain the benign development of the eco-environment of the lake basin.
