Project description:BackgroundWood is a secondary xylem generated by vascular cambium. Vascular cambium activities mainly include cambium proliferation and vascular tissue formation through secondary growth, thereby producing new secondary phloem inward and secondary xylem outward and leading to continuous tree thickening and wood formation. Wood formation is a complex biological process, which is strictly regulated by multiple genes. Therefore, molecular level research on the vascular cambium of different tree ages can lead to the identification of both key and related genes involved in wood formation and further explain the molecular regulation mechanism of wood formation.ResultsIn the present study, RNA-Seq and Pac-Bio Iso-Seq were used for profiling gene expression changes in Eucalyptus urophylla × Eucalyptus grandis (E. urograndis) vascular cambium at four different ages. A total of 59,770 non-redundant transcripts and 1892 differentially expressed genes (DEGs) were identified. The expression trends of the DEGs related to cell division and differentiation, cell wall biosynthesis, phytohormone, and transcription factors were analyzed. The DEGs encoding expansin, kinesin, cycline, PAL, GRP9, KNOX, C2C2-dof, REV, etc., were highly expressed in E. urograndis at three years old, leading to positive effects on growth and development. Moreover, some gene family members, such as NAC, MYB, HD-ZIP III, RPK, and RAP, play different regulatory roles in wood formation because of their sophisticated transcriptional network and function redundantly.ConclusionsThese candidate genes are a potential resource to further study wood formation, especially in fast-growing and adaptable eucalyptus. The results may also serve as a basis for further research to unravel the molecular mechanism underlying wood formation.
Project description:Fungal endophytes can protect plants against herbivory and be used to control leaf-cutting ants. In this study, we aimed to evaluate the potential of endophytic colonization of Eucalyptus urophylla by three filamentous fungal species and their influence on the plant development and foraging behavior of Atta sexdens. The study design was completely randomized and comprised a factorial scheme of 4 × 3, three antagonistic fungal species (Escovopsis sp., Metarhizium anisopliae, and Trichoderma strigosellum) of the leaf-cutting ant, and one control and three inoculation methods (conidial suspension via foliar spray [FS] and soil drench [SD] inoculation, and seedlings inoculated with mycelium [SWM]). The SWM method allowed T. strigosellum to colonize all plant organs, and these plants exhibited higher height, leaf number, shoot dry mass, and total dry mass than the ones subjected to the other inoculation methods. The SWM method increased the plant height than the control plants and those inoculated with Escovopsis sp. and M. anisopliae. Trichoderma strigosellum, previously isolated from soil, colonized E. urophylla plants and positively influenced their development, as demonstrated by the SWM method. Trichoderma strigosellum promoted the increase in E. urophylla height compared with when the FS and SD methods were used (by 19.62% and 18.52%, respectively). Our results reveal that A. sexdens workers preferentially began cutting the leaves from plants not previously colonized by T. strigosellum. This behavior can be explained by modifications in the phenotypic traits of the eucalyptus leaves.
Project description:In order to study the effect of polyploidization on gene expression in the leaves of Eucalyptus urophylla, triploid obtained by sexual polyploidization and its diploid control were used as materials, and leaves at different growth stages of different ploidies were collected for transcriptome sequencing.