Plant Molecular Biology Reporter最新文献

Lablab is a regionally important multipurpose legume crop used for human consumption, animal feed, and soil conservation. Despite these qualities, the potential value of this crop has not been fully utilized, and very little research attention has been given to it. The main objective of the study was molecular genetic diversity analysis of Lablab collections using 15 SSR markers. The molecular genetic diversity study of 91 Lablab collections revealed a total of 225 alleles with an average of 14.80 alleles per locus. All markers across the entire population were found to be highly polymorphic and informative with PIC values ranging from 0.78 to 0.92 with a mean value of 0.85. The average expected heterozygosity and gene diversity were 0.75 and 0.86 respectively, indicating a high level of diversity. Analysis of molecular variance showed that 94% of the total genetic variation was attributed to within populations, while only 6% was attributed to among populations. The fixation index value (0.061) recorded indicates the presence of moderate population differentiation as a result of high gene flow (Nm = 3.820) among populations. Due to high gene flow, Cluster, PCoA, and structure analysis did not exactly categorize the populations into genetic groups corresponding to their geographic origin. The observed relatively higher genetic diversity in Konso and West Wellega populations among the eight populations indicates that these areas could be considered hot-spots for genetic diversity and possible germplasm evaluation. Generally, genetic diversity obtained from this study provides inputs for Lablab conservation and improvement in Ethiopia.

Stephania tetrandra S. Moore (family: Menispermaceae), a dioecious herbaceous vine and the only species in the subgenus Botryodiscia of the genus Stephania of the family Menispermaceae, is mainly distributed in hilly areas south of the Huaihe River in China and found in many provinces of China, showing a high genetic diversity. This paper aimed to study genetic diversity of and genetic relationship among individuals of S. tetrandra within China to provide a basis for evaluation, exploitation, and utilization of S. tetrandra by using simple sequence repeat (SSR) molecular markers. Our results show that effective products were amplified from the 26 screened SSR gene loci, a total of 183 alleles amplified (2–16 alleles amplified by each pair of primers). Among the 26 loci, 16 had a PIC value higher than 0.5, indicating a high level of polymorphism. For most of the loci, the number of effective alleles was lower than that of the observed alleles, and the observed heterozygosity was lower than the expected heterozygosity. The genetic differentiation coefficient (0.021–0.547) was lower than 0.05 (low level of genetic differentiation) for 7 loci and higher than 0.25 (very high level of genetic differentiation) for 2 loci, and had a value representing a medium level of genetic differentiation for the remaining 17 loci. The intra-population inbreeding coefficient had a positive value for 21 loci, suggesting the presence of inbreeding and homozygous excess. The gene flow value was bigger than 1, indicating that genetic drift and natural selection played an unimportant role in population genetic differentiation of S. tetrandra. Based on discriminant analysis of principal components and Bayesian Information Criterion, K-means clustering was performed on 620 samples. These samples were divided into 9 genetic clusters, whose similarity coefficients and genetic distances were 0.755–0.918 and 0.067–0.280, respectively, indicating that these clusters were highly similar and short-distanced. The Bayesian clustering analysis was implemented in the STRUCTURE software to analyze the genetic structure of S. tetrandra and it was found that the 620 samples could be clustered into 5 ancestor groups; the 9 clusters and 40 natural populations inherited genes from the 5 groups to varying degrees, but the proportion of genes inherited from the 5 groups by each cluster and natural population differed. S. tetrandra was characterized by the presence of population structure and pronounced genetic subdivision, which, together with the presence of gene flow, may indicate a relatively stable recent state of these populations.

Saline-alkali stress has adverse effects on plant growth. Some plant Na⁺/H⁺ antiporters were reported to be important in salt tolerance. However, it needs to be better understood that Na⁺/H⁺ antiporters are involved in plant salt-alkali (NaHCO₃/Na₂CO₃) tolerance. In this study, a Na⁺/H⁺ antiporter gene LcNHX1 (China patent No.200810050629.1) has been cloned from Leymus chinensis. The LcNHX1 CDS contains 1614 bp that encodes 537 amino acids. Amino acid and nucleotide sequence similarity, protein topology modelling, conserved functional domains in the protein sequence, and subcellular localization classified LcNHX1 as a vacuolar NHX1 homolog. Transcription analysis by quantitative RT-PCR indicated that upregulated expression of LcNHX1 could be induced by NaCl, NaHCO₃, NaCl + NaHCO₃, and PGE in L. chinensis seedlings. The expression of LcNHX1 partially complements the salt-sensitive phenotypes of a Δnhx1 yeast strain. In addition, LcNHX1 overexpressing enhanced the tolerance to NaHCO₃ stress in the transgenic Arabidopsis. Taken together, these results indicated that LcNHX1 is a potential candidate gene for enhancing plant saline-alkali tolerance.

Abstract

High-altitude regions like the Himalaya, where various slopes are present on a very small spatial scale, are one of the best natural laboratories for investigating how genetic diversity and population structure are distributed across altitudinal gradients. In this study, we investigate the magnitude of genetic diversity and population structure of Rhododendron anthopogon D.Don along an altitudinal gradient in the Kashmir Himalaya. We used the start codon targeted (SCoT) marker to evaluate the genetic diversity and differentiation between different populations across five sites along an altitudinal gradient ranging from 3200 to 4000 m (amsl). Our results demonstrate that the magnitude of genetic diversity differs among the populations of R. anthopogon along the altitudinal gradient. We observed a decreasing trend in genetic diversity with increasing altitude from site-1 to site-3 (3200 to 3600 m), and an increasing trend from site-4 to site-5 (3601 to 4000 m). Furthermore, we also observed the highest genetic diversity at upper altitude (site-5) and the lowest at mid-altitude (site-3). Our results reveal a high genetic differentiation (G_st = 0.7349) and a low gene flow (N_m = 0.1804) among the populations. Analysis of molecular variance (AMOVA) reveals 71% variation among the populations and 29% variation within the populations. We also reveal positive associations between geographic and genetic distances, indicating isolation by distance effect across all altitudes. STRUCTURE and cluster analysis divided all the populations of R. anthopogon into five clusters according to their geographical location. Overall, the study adds to our understanding that altitude is the major driver of genetic variation and differentiation between populations of R. anthopogon which may help increase its range under ongoing projected climate change. Our study also reveals that populations at higher altitudes are not genetically isolated, suggesting that they might be an essential source for migration in the era of climate change.

The physical and chemical properties of tobacco (Nicotiana tabacum L.) plants are sensitive to changes in genetics and the environment. However, few studies have investigated the effect of both cultivar and regional factors on tobacco quality at the proteomic level. Here, a TMT-based quantitative proteomics method was used to investigate proteome profiling of different tobacco leaves under various geographical locations. In total, 8587 proteins were detected, among which 300 differentially abundant proteins (DAPs) were identified. Proteins associated with carbohydrate metabolism and amino acid metabolism were more abundant in tobacco plants from Yunnan. In contrast, proteins involved in the response to heat were more abundant in tobacco plants from Henan. We found that proteins related to carbon metabolism and defense signaling played an important role in the characteristics of different cultivars within the same region. In this work, we identified key proteins and pathways involved in the response of Nicotiana tabacum to environmental change and explored the proteomic differences among cultivars. Our results provide a better understanding of the effect of environment and cultivar on the tobacco leaf proteome, which will be helpful for elucidating the molecular mechanisms of the formation of tobacco characteristic quality.

Abstract

Sesamum indicum is an important oilseed crop rich in nutrients and antioxidants, cultivated worldwide owing to its economic value. Sesame fields are often challenged due to a disease caused by Candidatus Phytoplasma, a cell wall-lacking bacteria. Phytoplasma infection results in alteration in the plant’s physiological and metabolic responses. As metabolites are the final products that aid in a plant’s adaptation to several biotic and abiotic stresses, it is necessary to understand these metabolic changes. However, the changes at the metabolite level after Phytoplasma infection in sesame are poorly understood. To investigate the response of sesame plants to Phytoplasma infection, we analyzed the metabolic changes using liquid chromatography-tandem mass spectrometry (LC–MS/MS/MS). Data analysis led to the detection of 162 metabolites, among which 82 were upregulated, while 62 exhibited downregulating trends in the Phytoplasma-infected tissue. The upregulated metabolites include flavonoids, phenolics, lignans, glucosinolates, terpenoids, phytohormones, and some sugars, like trehalose. Phytoplasma infection also resulted in significant chlorophyll breakdown, suggesting impaired chloroplast physiology. We have also validated this LC–MS/MS data by biochemical analysis and analyzing the expression of a few genes behind the biosynthesis of the concerned metabolites using qRT-PCR analysis. The results indicate that plant metabolic networks undergo reprogramming upon Phytoplasma infection. Understanding this altered metabolic pathway may aid in developing a control measure for this disease.

Enhancing water use efficiency is a key strategy to improve drought resistance in cotton. Although drought priming has been recognized for enhancing plant tolerance to drought, its impact on upland cotton remains uncertain. In a pot trial with Xinluzao19, we studied the influence of soil drought and drought priming on seedlings. Primed plants maintained similar height to non-primed ones but showed significant differences in hydrogen peroxide, malondialdehyde, and enzyme activities, indicating improved reactive oxygen species (ROS) homeostasis. Transcriptome analysis revealed 1441 upregulated genes and 12,024 downregulated genes in RD6D compared to D6D. GO enrichment and KEGG metabolic pathway analysis also revealed that numerous stress-related genes and defense pathways were significantly enriched. Some genes linked to ascorbate peroxidase and superoxide dismutase displayed similar expression profiles with enzymatic activities. These insights contribute to enhancing cotton and overall crop productivity, particularly under water-deficit conditions.

Horsegram (Macrotyloma uniflorum) is an important legume crop well adapted to harsh environments and has significant nutritional value. It is also well recognized due to its nutritional value, health benefits, drought tolerance, and ability to improve soil fertility. It is a versatile crop used in various dishes and is a valuable addition to any diet. However, in-depth molecular analysis must be improved to understand the molecular architecture regulating the essential traits. To achieve this, the study utilized a genome-wide association mapping approach using 88 horsegram accessions genotyped with 55,656 single nucleotide polymorphisms (SNPs). A total of 54,271 SNPs were mapped to the reference genome. Phenotypic data were collected for four agronomic and yield-related traits: plant height, days to maturity, days to flowering, and number of branches per plant. These traits played a significant role in plant growth, development, protection, and crop yield. The study identified 79 significant SNP-trait associations for the traits under study. The identified SNPs were in 8 chromosomes. The study also identified several novel genomic regions associated with the traits considered, providing new insights into the genetic basis of these essential traits in horsegram. Overall, the study highlights the potential of genome-wide association mapping for identifying genomic regions associated with important agronomic and yield-related traits in horsegram. This could facilitate the development of improved horsegram varieties through marker-assisted breeding programmes and overcoming the morphological selection of desirable genotypes in the background of narrow genetic base.

Blossom end rot (BER) is mainly a calcium (Ca²⁺) deficiency-related physiological disorder of fruits that affects various crop production worldwide including tomato (Solanum lycopersicum). The visible symptoms of BER include cell wall disintegration, cell plasmolysis, and water-soaked signs at the distal end of the fruits. During fruit development increase in cell expansion and a decrease in the transport of Ca²⁺ to the distal part of the fruits, can lead to the development of BER. It is hypothesized that insufficient Ca²⁺ is available for essential apoplastic and cytoplasmic functions during the cell expansion phase of fruits when the cellular Ca²⁺ demand exceeds the Ca²⁺ supply. Therefore, abnormal intracellular Ca²⁺ content or signals, cause weakening of cell walls, and a loss of cellular integrity, potentially leading to cell death and the outward manifestations of BER. The occurrence of BER in tomatoes is also influenced by environmental factors that affect the cellular growth of the fruits. These factors such as drought, high salinity, high temperature, insufficient xylem tissue development, phytohormones, and oxidative stress can influence the development of BER. The availability of a high-quality reference genome and whole genome sequencing allowed us to identify selected loci that can cause BER, facilitating genetic dissection and a deeper comprehension of the molecular mechanisms underlying this disorder. This review summarized the various factors and genes involved in BER development and management strategies.

Maize (Zea mays) represents one of the most successful uses of heterosis among crops. Hybrid maize seeds can be produced by crossing a male-sterile female parent with a male parent as the pollen donor to achieve high seed purity at low cost. Cytoplasmic male sterility (CMS) has been widely used for maize hybrid seed production. Recently, several hybrid seed production technologies based on genic male sterility (GMS) genes have been developed. In addition, the identification of environment-sensitive genic male sterility (EGMS) genes provides opportunities for the two-line system to be applied in maize hybrid seed production. In this review, we systematically summarize the male-sterile genes and molecular mechanisms of male sterility in maize. Future prospects for the study of maize male sterility are highlighted. Future research will enhance our understanding of the molecular regulatory networks of male sterility and promote the process of maize hybrid seed production using male sterile lines.