Application of Developmental Regulators for Enhancing Plant Regeneration and Genetic Transformation.

Establishing plant regeneration systems and efficient genetic transformation techniques plays a crucial role in plant functional genomics research and the development of new crop varieties. The inefficient methods of transformation and regeneration of recalcitrant species and the genetic dependence of the transformation process remain major obstacles. With the advancement of plant meristematic tissues and somatic embryogenesis research, several key regulatory genes, collectively known as developmental regulators, have been identified. In the field of plant genetic transformation, the application of developmental regulators has recently garnered significant interest. These regulators play important roles in plant growth and development, and when applied in plant genetic transformation, they can effectively enhance the induction and regeneration capabilities of plant meristematic tissues, thus providing important opportunities for improving genetic transformation efficiency. This review focuses on the introduction of several commonly used developmental regulators. By gaining an in-depth understanding of and applying these developmental regulators, it is possible to further enhance the efficiency and success rate of plant genetic transformation, providing strong support for plant breeding and genetic engineering research.

The Metasequoia genome and evolutionary relationships among redwoods.

Redwood trees (Sequoioideae), including Metasequoia glyptostroboides (dawn redwood), Sequoiadendron giganteum (giant sequoia), and Sequoia sempervirens (coast redwood), are threatened and widely recognized iconic tree species. Genomic resources for redwood trees could provide clues to their evolutionary relationships. Here, we report the 8-Gb reference genome of M. glyptostroboides and a comparative analysis with two related species. More than 62% of the M. glyptostroboides genome is composed of repetitive sequences. Clade-specific bursts of long terminal repeat retrotransposons may have contributed to genomic differentiation in the three species. The chromosomal synteny between M. glyptostroboides and S. giganteum is extremely high, whereas there has been significant chromosome reorganization in S. sempervirens. Phylogenetic analysis of marker genes indicates that S. sempervirens is an autopolyploid, and more than 48% of the gene trees are incongruent with the species tree. Results of multiple analyses suggest that incomplete lineage sorting (ILS) rather than hybridization explains the inconsistent phylogeny, indicating that genetic variation among redwoods may be due to random retention of polymorphisms in ancestral populations. Functional analysis of ortholog groups indicates that gene families of ion channels, tannin biosynthesis enzymes, and transcription factors for meristem maintenance have expanded in S. giganteum and S. sempervirens, which is consistent with their extreme height. As a wetland-tolerant species, M. glyptostroboides shows a transcriptional response to flooding stress that is conserved with that of analyzed angiosperm species. Our study offers insights into redwood evolution and adaptation and provides genomic resources to aid in their conservation and management.

Association between rs1800629 polymorphism in tumor necrosis factor-α gene and dilated cardiomyopathy susceptibility: Evidence from case-control studies.

OBJECTIVE: Several published studies have investigated the association between the -308G/A (rs1800629) polymorphism in the tumor necrosis factor-α (TNF-α) gene and the risk of dilated cardiomyopathy (DCM). However, the TNF-α gene polymorphism has a controversial role in the pathogenesis of DCM among different populations. In the present study, a meta-analysis was performed to resolve this inconsistency. METHODS: Potentially eligible papers reporting an association between the TNF-α rs1800629 polymorphism and DCM susceptibility were searched in 4 databases including PubMed, EMBASE, Chinese Biomedical Database (CBM), and the Cochrane Library up to April 1, 2018. The odds ratio (OR) with its 95% confidence interval (CI) was used to estimate the strength of the associations. Subgroup analysis based on the ethnicity, studies with or without ischemic and valvular DCM was conducted. Publication bias detection was conducted using Begg test. RESULTS: Nine papers detailing case-control studies were included, reporting a total of 1339 DCM cases and 1677 healthy controls. The meta-analysis results indicated that TNF-α rs1800629 was associated with increased DCM susceptibility in the populations studied under the heterozygous model (AG vs GG: OR = 1.91, 95% CI = 1.05-3.50, P = .035) and dominant model (AG + AA vs GG: OR = 1.87, 95% CI = 1.01-3.45, P = .046). In the subgroup analysis for ethnicity, rs1800629 polymorphism was significantly associated with the susceptibility of DCM for Asians under the 5 models (A vs G: OR = 2.87, 95% CI = 1.56-5.30, P = .001; AA vs GG: OR = 3.95, 95% CI = 1.13-13.82, P = 0.031; AG vs GG: OR = 3.8, 95% CI = 1.57-9.19, P = .003; AA vs GG + AG: OR = 2.51, 95% CI = 1.41-4.49, P = .002; AG + AA vs GG: OR = 3.77, 95% CI = 1.54-9.20, P = .004). CONCLUSION: There may be a moderate association between TNF-α rs1800629 polymorphism and DCM susceptibility in the whole populations studied; however, TNF-α rs1800629 polymorphism was significantly associated with the susceptibility of DCM for Asians, which indicates that such associations may be different between ethnicities.