Transcriptome-Based Construction of the Gibberellin Metabolism and Signaling Pathways in Eucalyptus grandis × E. urophylla, and Functional Characterization of GA20ox and GA2ox in Regulating Plant Development and Abiotic Stress Adaptations

Abstract

Gibberellins (GAs) are the key regulators controlling plant growth, wood production and the stress responses in perennial woody plants. The role of GA in regulating the above-mentioned processes in Eucalyptus remain largely unclear. There is still a lack of systematic identification and functional characterization of GA-related genes in Eucalyptus. In this study, a total of 59,948 expressed genes were identified from the major vegetative tissues of the E. grandis × E. urophylla using transcriptome sequencing. Then, the key gene families in each step of GA biosynthesis, degradation and signaling were investigated and compared with those of Arabidopsis, rice, and Populus. The expression profile generated using Real-time quantitative PCR showed that most of these genes exhibited diverse expression patterns in different vegetative organs and in response to abiotic stresses. Furthermore, we selectively overexpressed EguGA20ox1, EguGA20ox2 and EguGA2ox1 in both Arabidopsis and Eucalyptus via Agrobacterium tumefaciens or A. rhizogenes-mediated transformation. Though both Arabidopsis EguGA20ox1- and EguGA20ox2-overexpressing (OE) lines exhibited better vegetative growth performance, they were more sensitive to abiotic stress, unlike EguGA2ox1-OE plants, which exhibited enhanced stress resistance. Moreover, overexpression of EguGA20ox in Eucalyptus roots caused significantly accelerated hairy root initiation and elongation and improved root xylem differentiation. Our study provided a comprehensive and systematic study of the genes of the GA metabolism and signaling and identified the role of GA20ox and GA2ox in regulating plant growth, stress tolerance, and xylem development in Eucalyptus; this could benefit molecular breeding for obtaining high-yield and stress-resistant Eucalyptus cultivars.

Endogenous Hormone Levels and Transcriptomic Analysis Reveal the Mechanisms of Bulbil Initiation in Pinellia ternata

“…GA biosynthesis is a complicated pathway that is mainly catalyzed by seven key steps: CPS, KS, KO, KAO, GA13ox, GA20ox, and GA3ox [ 76 ]. GA20ox serves as the rate-limiting enzyme in the synthesis of GA [ 77 ]. The deactivation of bioactive GAs is controlled by several distinct groups of enzymes, among which GA2ox plays a pivotal role [ 76 ].…”

Important Factors Controlling Gibberellin Homeostasis in Plant Height Regulation

“…Wu et al used the third-generation transcriptome sequencing strategy PacBio Iso-Seq to analyze the regulatory network associated with GA in Eucalyptus. 86 High-throughput sequencing is increasingly used as the sequencing costs decrease. This method has improved gene resolution and aided in the discovery of quantitative trait loci, thus providing many new opportunities for exploring the relationships between genotypes and phenotypes.…”

“…With advances in molecular biology and genomics, more genes are being identified through map-based cloning, GWAS, RNA sequencing, and other technologies and are being applied to the cultivation of excellent varieties. Wu et al used the third-generation transcriptome sequencing strategy PacBio Iso-Seq to analyze the regulatory network associated with GA in Eucalyptus . High-throughput sequencing is increasingly used as the sequencing costs decrease.…”

Effect of Chitosan and Gibberellic Acid on Fruit Yield and Production of Peach (<i>Prunus persica</i> L.)

“…The results are similar to those of [16] they reflect enhance of fruit influence by purpose of gibberellic acid in stone fruit. The result is linked among introduce [17] they describe to foliar apply of 0.05% chitosan at 7 days, opening since on 14 days in the wake of transplant) expand ordinary result influence, expected effect measurement, and give in of timer pepper (Capsicum annum).…”