Formation mechanism and regulation analysis of trumpet leaf in Ginkgo biloba L.

Introduction: The research on plant leaf morphology is of great significance for understanding the development and evolution of plant organ morphology. As a relict plant, the G. biloba leaf morphology typically exhibits bifoliate and peltate forms. However, throughout its long evolutionary history, Ginkgo leaves have undergone diverse changes. Methods: This study focuses on the distinct "trumpet" leaves and normal fan-shaped leaves of G. biloba for analysis of their phenotypes, photosynthetic activity, anatomical observations, as well as transcriptomic and metabolomic analyses. Results: The results showed that trumpet-shaped G. biloba leaves have fewer cells, significant morphological differences between dorsal and abaxial epidermal cells, leading to a significantly lower net photosynthetic rate. Additionally, this study found that endogenous plant hormones such as GA, auxin, and JA as well as metabolites such as flavonoids and phenolic acids play roles in the formation of trumpet-shaped G. biloba leaves. Moreover, the experiments revealed the regulatory mechanisms of various key biological processes and gene expressions in the trumpet-shaped leaves of G. biloba. Discussion: Differences in the dorsal and abdominal cells of G. biloba leaves can cause the leaf to curl, thus reducing the overall photosynthetic efficiency of the leaves. However, the morphology of plant leaves is determined during the primordia leaf stage. In the early stages of leaf development, the shoot apical meristem (SAM) determines the developmental morphology of dicotyledonous plant leaves. This process involves the activity of multiple gene families and small RNAs. The establishment of leaf morphology is complexly regulated by various endogenous hormones, including the effect of auxin on cell walls. Additionally, changes in intracellular ion concentrations, such as fluctuations in Ca2+ concentration, also affect cell wall rigidity, thereby influencing leaf growth morphology.

[Research on systematic evolution of ginkgo biloba based on chemical composition of wood].

In the present article, the authors mensurated the infrared spectra of 22 conifer and broadleaf trees such as ginkgo biloba L., cycas revoluta thunb., Populus tomentosa Carr and so on using FTIR, analyzed the difference of a number of absorb peaks in fingerprint area, the characteristic absorb peak position of cellulose and lignin of these trees and their alternation regulations of relative intensity, then discussed the evolutional issue of ginkgo biloba. The results show that ginkgo biloba is different from cycas in the infrared spectra of wood but similar to the conifer trees, which illustrates the ginkgo biloba. is more evolutional than cycas in the timber's chemical composition but with similar affiliation to conifer trees. The content of lignin in the ginkgo biloba wood is more than that in other conifer trees, which may be a original character of ginkgo biloba. Meanwhile, the ginkgo biloba has some syringyl lignins in addition to guaiacyl, and it has the evolutional tendency for broadleaf trees.

Genetic relationships of ornamental cultivars of Ginkgo biloba analyzed by AFLP techniques.

Eight primer combinations that produced clear and a large number of polymorphic bands were screened from 64 EcoR I/Mse I primer combinations (Mse I fluorescent labeled). The genetic relationships of 21 ornamental cultivars of Ginkgo biloba L. from the United States of America, Holland, Japan, France, and China were analyzed. These primer combinations produced a total of 1 119 bands, 229 specific loci (including 54 absent bands, and 175 monomorphic bands). Among them, 983 polymorphic bands (PPB), accounting for 88%, were detected. The percentage of identification per primer combination was as high as 100%. The average PPB of 14 foreign cultivars was 35.86% and the average PPB of seven domestic cultivars was 31.51%. Genetic similarity coefficient (SC) among all cultivars varied from 0.4899 to 0.8499, and all cultivars were divided into the four clusters when SC was set at 0.7300. The cultivars from the same origin did not fall into the same group. The cultivars from France and China were classified into three groups. According to the comprehensive analyses based on specific loci, similarity coefficient, and clustering results, eight cultivars 'Fastigiata', 'Tit', 'Tubifolia', 'Daeryinxing', 'Variegata', 'Horizontalis, 'Pendula', and 'Yiyuanyeziyinxing' were considered to be important germplasms of ornamental cultivars of Ginkgo biloba.

[Quantitative genetic analysis and multiple trait selection of pharmaceutical composition on Ginkgo biloba L. leaves].

The China possesses more than 70% Ginkgo resources in the world. The purposes of this research are to collect fine seedling and grafting clones in China, to probe genetic law on flavone glycosides and terpenes on Ginkgo leaves, and select leaf-used cultivars of high-pharmaceutical composition. In this research, we have collected 87 clones from 13 provenances and have carried out randomized block experiment at Tancheng, Laizhou and Yaoxiang in Shandong Province. Flavone glycosides and terpenes were determined through HPLC method from an improved Van Beek (1991) techniques and Shimadzu Lc-10 AD (Japan). Data and breeding analyses were carried out through IBMPC and SPQG30 software. The results of variance analyses show that there are significant differences to flavone glycosides, terpenes in clones, and the law of genetic parameters on heritability (h2) and genetic variability coefficient (Gcv), is clone > sex > provenance to flavone glycosides in ginkgo leaves. The sigma g2, h2, Gcv and delta G' in male tree clone leaves are higher than female clone leaves on flavone glycosides. We have found that there is a maximum flavone content clone among males and a maximum terpene clone among females. The results of Q-cluster analyses are consistent with R-factor analyses of twenty higher terpenes clones. The results of index selection show that the ri.Y2, E(I) and CGS' of multiple traits selection including (gamma) trait are higher than single trait and multiple traits selection excluding gamma. The direct or index selection is more suited to leaf-used cultivars of Ginkgo. The genetic stability of each clone was appraised by Wricke's ecovalence method and Nassar & Huhu noparameter method. Flavone glycosides and terpenes are more than 2.09%-2.57% and 0.33%-0.41%, respectively, and we have selected four clones.