Genome-Wide Analysis of Genes Involved in the GA Signal Transduction Pathway in ‘duli’ Pear (Pyrus betulifolia Bunge)

Abstract

Gibberellic acid (GA) is an important phytohormone that regulates every aspect of plant growth and development. While elements involved in GA signaling have been identified and, hence, their functions have been well studied in model plants, such as Arabidopsis and rice, very little is known in pear. We, therefore, analyzed the genes related to GA signaling from the recently sequenced genome of the wildtype ‘duli’ pear (Pyrus betulifolia Bunge), a widely used rootstock for grafting in pear cultivation in China due to its vigorous growth and resistance to abiotic and biotic stress. In total, 15 genes were identified, including five GA receptors PbGID1s (GA-INSENSTIVE DWARF 1), six GA negative regulators, PbDELLAs, and four GA positive regulators, PbSLYs. Exogenous application of GA could promote the expression of PbGID1s but inhibit that of PbDELLAs and PbSLYs in tissue culture ‘duli’ pear seedlings. The expression profiles of these genes in field-grown trees under normal growth conditions, as well as in tissue-cultured seedlings treated with auxin (IAA), GA, paclobutrazol (PAC), abscisic acid (ABA), and sodium chloride (NaCl), were also studied, providing further evidence of the involvement of these genes in GA signaling in ‘duli’ pear plants. The preliminary results obtained in this report lay a good foundation for future research into GA signaling pathways in pear. Importantly, the identification and preliminary functional verification of these genes could guide molecular breeding in order to obtain the highly desired dwarf pear rootstocks for high-density plantation to aid easy orchard management and high yielding of pear fruits.

Integrated Transcriptomic and Metabolomic Analysis Reveals the Mechanism of Gibberellic Acid Regulates the Growth and Flavonoid Synthesis in Phellodendron chinense Schneid Seedlings

“…The Pc(S)-GA2ox unigene is involved in the conversion of its inactive form, indicating that GA 3 prevented GA biosynthesis and promoted its degradation in leaves of P. chinense Schneid seedlings [49,50]. The GID1B/C proteins as receptors recognized GA 3 that combined with DELLA protein to form a trimer, subsequently labeled by SCF SLY1 /GID2 complex and degraded through 26S protease, releasing the repression of DELLA protein and promoting cell elongation in plants [51,52]. Thus, the expression variations of Pc(S)-GID1/2 (downregulation) and Pc(S)-DELLA (upregulation) unigenes demonstrated that exogenous GA 3 inhibited the GA signal transduction in leaves of P. chinense Schneid seedlings, speculating that GA 3 may promote its growth by other phytohormones.…”

Isolation and characterization of Priestia megaterium KD7 for the biological control of pear fire blight

“…Two pear varieties, ‘duli’ pear ( Pyrus betulifolia Bunge) and Korla fragrant pear, were used to evaluate the biocontrol activity of antagonistic bacteria against E. amylovora. The detached leaves and twigs were selected from ‘duli’ pear, a wildtype pear widely used rootstock for grafting in China due to its resistance to biotic and abiotic stress ( Song et al, 2022 ). The fruits were collected from Korla fragrant pear ( Pyrus sinkiangensis Yü), a popular cultivated pear variety in China.…”