Search Results (6)

The MYB transcription factor family is one of the largest families of plant transcription factors (TFs), and it plays a vital role in the entire process of a plant’s growth and development. Well known in China, Eucommia ulmoides (E. ulmoides) produces a form of natural rubber called Eucommia ulmoides gum (EUG). Nevertheless, there is little research on the evolutionary history and expression patterns of its MYBs, as well as on the regulation of EUG by MYB TFs. This research provides a comprehensive description, classification, and potential functional analysis of the EuMYB gene family. A total of 119 MYB members of E. ulmoides were identified based on the whole genome sequencing data, and their gene structure, phylogenetics, chromosome location, conserved motifs, etc., were analyzed. Based on the phylogenetic tree results, EuMYBs could be divided into 35 sub-groups. In addition, chromosomal localization and collinearity analysis revealed the heterogeneous distribution of the MYB family in the E. ulmoides’ genome, indicating the expansion of its gene family. Moreover, promoter cis-acting elements showed that the promoter contained abundant light-responsive elements, anaerobic-induction-responsive elements, and abscisic-acid-responsive elements. A co-expression regulatory network between the EUG biosynthesis genes and the EuMYBs was built. Meanwhile, regarding the six EuMYBs with high expression in the gum-forming tissues selected that correlated with the farnesyl diphosphate synthase (FPS1) structural gene, RT-qPCR experiments showed a possible regulatory relationship between EuMYBs and FPS1, which played an important role in EUG biosynthesis. In conclusion, this paper defines a research gap and lays a foundation for further studies on the biological functions of EuMYBs. Full article

As an important temperate gum source plant, Eucommia ulmoides is widely distributed in China, but the low yield of Eucommia ulmoides gum considerably affects its application as a natural rubber in practical production. The small rubber particle protein (SRPP) gene is an influential participant in the Eucommia ulmoides gum biosynthesis process, and its expression affects the gum content. In this study, the promoter activity of the Eucommia ulmoides SRPP (EuSRPP) gene was analyzed by molecular biology and bioinformatics. In order to understand the molecular regulation mechanism of the EuSRPP genes at the transcriptional level, we first obtained the promoter sequences of the EuSRPP1, 3, 4, 5, 6, and 7 genes via genome walking and PCR amplification experiments. Then, the T3 generation of the transgenic homozygous line was obtained via a genetic transformation of Arabidopsis thaliana mediated by Agrobacterium. The six EuSRPP promoters were expressed in transgenic plants and were stably expressed in the leaves, pollinated flowers, and mature pods. As the transgenic plant grows and develops, promoter activity in the root is barely expressed. In addition, after the transgenic Arabidopsis was treated with methyl jasmonate (1 mmol/L MeJA), gibberellin (1 mmol/L GA3), and drought (20% PEG6000), the activity expression of the six EuSRPP promoters increased first and then decreased. The difference, however, is that EuSRPP1, 3, and 4 reach their strongest GUS activity at 3 h of plant treatment, while EuSRPP5, 6, and 7 reach their strongest activity at 6 h of treatment. Based on all experimental results, for the first time, it has been shown that the expression loci of the six EuSRPP gene promoters were relatively consistent. Second, the expression activity of the promoters of the six EuSRPP genes was different under MeJA, GA3, and drought treatment, suggesting that the promoter activity of the EuSRPP genes was regulated by endogenous hormones and drought pathways. Full article

Eucommia ulmoides gum (EUG) is a natural polymer predominantly consisting of trans-1,4-polyisoprene. Due to its excellent crystallization efficiency and rubber-plastic duality, EUG finds applications in various fields, including medical equipment, national defense, and civil industry. Here, we devised a portable pyrolysis-membrane inlet mass spectrometry (PY-MIMS) approach to rapidly, accurately, and quantitatively identify rubber content in Eucommia ulmoides (EU). EUG is first introduced into the pyrolyzer and pyrolyzed into tiny molecules, which are then dissolved and diffusively transported via the polydimethylsiloxane (PDMS) membrane before entering the quadrupole mass spectrometer for quantitative analysis. The results indicate that the limit of detection (LOD) for EUG is 1.36 μg/mg, and the recovery rate ranges from 95.04% to 104.96%. Compared to the result of pyrolysis-gas chromatography (PY-GC), the average relative error is 1.153%, and the detection time was reduced to less than 5 min, demonstrating that the procedure was reliable, accurate, and efficient. The method has the potential to be employed to precisely identify the rubber content of natural rubber-producing plants such as Eucommia ulmoides, Taraxacum kok-saghyz (TKS), Guayule, and Thorn lettuce. Full article

Eucommia ulmoides, a single extant species of Eucommiaceae, is a perennial deciduous tree distributed across central China. The bark of E. ulmoides is rich in chlorogenic acid and flavonoids that possesses high medicinal value, whereas its leaves and seeds contain abundant Eucommia ulmoides gum (EUG), which is a unique strategic resource in China that can be used as a substitute for natural rubber. Under the background of global warming, the evaluation of habitat suitability is of great significance for the protection and management of E. ulmoides. For this study, maximum entropy (MaxEnt) modeling was employed to simulate the potentially suitable region for E. ulmoides over four periods (current, 2050s, 2070s, and 2090s) under four climate change scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5), as well as to analyze changes in the spatial patterns of E. ulmoides and the essential environmental factors affecting the growth and distribution of E. ulmoides. The results revealed that the current potentially suitable region for E. ulmoides was 211.14 × 10⁴ km², which accounted for 21.99% of China’s territory. The low impact areas for E. ulmoides were distributed in Guizhou, Zhejiang, Sichuan, eastern Chongqing, southern Shaanxi, western Hubei, eastern Shandong, southern Anhui, southern Gansu, and northern Yunnan Provinces. The key bioclimatic variables affecting the distribution of E. ulmoides were mean diurnal range and mean temperature of the coldest quarter, with their contribution rates of 53.8% and 41.4%, respectively. Furthermore, core distributional shift analysis indicated that the center of the potentially suitable regions of E. ulmoides exhibited a general trend of shifting to the northwest and high latitudes. Finally, conservation strategies are proposed, such as the establishment of ex situ protection sites and germplasm resource collection. Future researchers can conduct further studies by integrating the quality of E. ulmoide herbs and environmental variables. In this study, for technical reasons, we only considered the effect of climate on species distribution without considering other biotic and abiotic factors, which can be further addressed by future researchers. Full article

Novel, fully biobased shape memory thermoplastic vulcanizates (TPVs) were prepared using two sustainable biopolymers, poly(lactic acid) (PLA), and modified natural Eucommia ulmoides gum (EUG-g-GMA), via a dynamic vulcanization technique. Simultaneously, in situ compatibilization was achieved in the TPVs to improve interfacial adhesion and the crosslinked modified Eucommia ulmoides gum (EUG) was in “netlike” continuous state in the PLA matrix to form “sea-sea” phase structure. The promoted interface and co-continuous structure played critical roles in enhancing shape memory capacity and toughness of the TPVs. The TPV with 40 wt % modified EUG displayed the highest toughness with an impact strength of 54.8 kJ/m² and the most excellent shape memory performances with a shape fixity ratio (R_f) of 99.83% and a shape recovery ratio (R_r) of 93.74%. The prepared shape memory TPVs would open up great potential applications in biobased shape memory materials for smart medical devices. Full article

A series of shape memory blends of natural Eucommia ulmoides gum (EUG) and low-density polyethylene (LDPE) with a bicontinuous cross-linked structure were prepared by a physical blending method, which could be used in the field of thermal response with two different temperatures. We report the shape memory properties of these blended materials with two response temperatures for the first time. The mechanical, curing, thermal and shape memory properties of the blends were studied in this manuscript. Schematic diagrams are proposed to illustrate the dual shape memory behaviors of the EUG/LDPE blends. Our study focused on observing the relationship between the shape memory behavior and the microscopic crystalline phase states in the blends. In the blends, both the cross-linked network and the LDPE crystalline regions could act as fixed domains, while the crystalline regions of LDPE or EUG could act as the reversible domain. The shape memory properties were mainly determined by the components of the fixed and reversible domains. We focused on the shape memory behavior of blends at 60 °C and 130 °C in this manuscript. The results showed that when the peroxide dicumyl peroxide (DCP) dosage was 1.0 phr, the blends exhibited acceptable shape behavior at 60 °C (R_1f = 74.8%, R_1r = 63.3%). At the same time, when DCP dosage was 0.4 phr, the shape memory behavior of the blends at 130 °C was good and much better than that at 60 °C (R_2f = 91.1%, R_2r = 89.4%). Full article