Section for Crop Sciences, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Taastrup, Denmark.
Plant Sci. 2024 Nov;348:112209. doi: 10.1016/j.plantsci.2024.112209. Epub 2024 Aug 3.
Transformation of plants using wild strains of agrobacteria is termed natural transformation and is not covered by GMO legislation in e.g. European Union and Japan. In the current study, offspring lines (A11 and B3) of Rhizobium rhizogenes naturally transformed oilseed rape (Brassica napus) were randomly selected to characterize the morphological traits, and analyze the implications of such morphological changes on plant drought resilience. It was found that the introduction of Ri-genes altered the biomass partitioning to above- and under-ground parts of oilseed rape plants. Compared to the wild type (WT), the A11 and B3 lines exhibited 1.2-4.0 folds lower leaf and stem dry weight, leaf area and plant height, but had 1.3-5.8 folds greater root dry weight, root length and root surface area, resulting in a significantly enhanced root: shoot dry mass ratio and root surface area: leaf area ratio. In addition, the introduction of Ri-genes conferred reduced stomatal pore aperture and increased stomatal density in the B3 line, and increased leaf thickness in A11 line, which could benefit plant drought resilience. Finally, the modulations in morphological traits as a consequence of transformation with Ri-genes are discussed concerning resilience in water-limited conditions. These findings reveal the potential of natural transformation with R. rhizogenes for drought-targeted breeding in crops.
利用野生型根瘤农杆菌菌株对植物进行转化被称为自然转化，这在例如欧盟和日本的转基因生物立法中并不涵盖。在本研究中，随机选择根瘤农杆菌自然转化的油菜（甘蓝型油菜）的后代系（A11 和 B3）来表征形态特征，并分析这种形态变化对植物抗旱性的影响。结果发现，Ri 基因的导入改变了油菜植物地上和地下部分的生物量分配。与野生型（WT）相比，A11 和 B3 系的叶片和茎干重、叶面积和株高分别降低了 1.2-4.0 倍，但根干重、根长和根表面积分别增加了 1.3-5.8 倍，导致根：茎干质量比和根表面积：叶面积比显著增加。此外，Ri 基因的导入导致 B3 系气孔孔径减小和气孔密度增加，A11 系叶片厚度增加，这有利于植物抗旱性。最后，讨论了由于 Ri 基因转化而导致的形态特征的调节与在限水条件下的恢复力之间的关系。这些发现揭示了利用根瘤农杆菌进行自然转化在作物抗旱性靶向育种方面的潜力。
