Plant Molecular Biology Reporter最新文献

Self-(in)compatibility (SI) is a genetic barrier developed by flowering plants to prevent self-pollination and promote outcrossing. SI is one of the most important traits in stone fruit breeding and particularly in apricot. Indeed, researchers focused their interests on identifying and selecting self-(in)compatible apricot parents for breeding programs and cultivars for the installation of new plantations. In this context, SI was studied in a set of 65 Tunisian apricot accessions focusing on both S and M loci targeting the genes, S-RNase, SFB, and ParMDO, with different primer combinations. The amplification of the first and the second intron of the S-RNase gene allowed the identification of nine different S alleles. The S₇ allele which is reported to be present only in Southern Europe and North Africa regions was the most frequent occurring in 24 genotypes. Moreover, self-pollination tests and amplification of the SFB and ParMDO gene insertions (S_C and m haplotypes) producing pollen-part mutations (PPMs) that confer self-compatibility (SC) allowed us to correlate the presence of these two independent PPMs with SC for the first time within Tunisian apricot germplasm. Overall, nine accessions were found to be self-compatible carrying at least one self-compatible haplotype. The distribution of S alleles in the analyzed accessions supported the introduction of apricot to North Africa from the Irano-Caucasian region. Moreover, the detection of the self-compatible ParMDO m haplotype in Kairouan accessions similar to Spanish cultivars confirmed gene flow between Western European and North African apricots. All these results may provide relevant information for apricot breeding and production.

The molecular mechanism of flower development and sexual differentiation, which is an intricate process, still unclear in Vitis plants. In this study, we performed the transcriptome analysis by high-throughput sequencing to measure gene expression at three stages in male, female, and hermaphrodite grape flowers, and in combination with the fluctuation of hormones (ABA, IAA, BR, GA3, and JA) to understand the gene function and molecular basis of developmental processes in Vitis flowers. The results showed that more than 581 million clean reads were generated from all samples and average 83% reads were mapped on the Vitis vinifera genome. More, quite a large number of genes were differentially expressed between different stages within and across cultivars and various transcription factor families involved were identified in flower development. The genes belonging to MYB, bHLH, ERF, NAC, and WRKY have more numbers than other TF families. Furthermore, we analyzed the correlation of those hormones with 165 DEGs (including 36 TF genes). The results suggested that those genes might play important roles in sex differentiation during flower development and a unique opportunity to increase the efficiency of crossbreeding in Vitis plant.

Histone acetylation plays important roles in gene regulation and is catalyzed by histone acetyltransferases (HATs). The performance of histone acetylation by HATs requires the involvement of other proteins to form multi-subunit complexes. The functions of three major HAT-containing complexes, namely SAGA, NuA4, and TFIID, have been extensively studied. Recently, the MEDIATOR complex was also found to be associated with HAT in Arabidopsis. However, these complexes have rarely been investigated in other plant species. In this study, we identify the subunits of four HAT-containing complexes in six different grass species by using Arabidopsis homologs as reference sequences. We then construct the phylogenetic trees to analyze their evolutionary relationships. The results indicate that all six grass species conserve all the subunits, despite gene duplication events occurring diversely in different species. Expression analysis shows that most of the genes encoding the subunits of the four HAT-containing complexes are constitutively expressed, with only low-level expression in pollen. Consistent with their cellular function, all four HATs are found to be localized in the nucleus in sorghum. Unlike their Arabidopsis counterparts, SbGCN5 specifically acetylates H3K4, H3K9, and H3K27, while SbMYST acetylates H4K5 and H4K12 in vitro. Additionally, we discover that SbTAF1 catalyzes acetylation of H3K9 and H4K5 for the first time. These findings provide valuable insights for further investigations into the function of HAT-containing complexes in grass species.

Flowering is the change from the vegetative state to the reproductive state. Flowering initiation is regulated by endogenous genetic components and by numerous environmental factors. These stimuli determine the different molecular mechanisms that are required to give way to flowering and vary according to the dose of the stimulus and the crop used. Jatropha curcas is a perennial shrub that produces oil from its seeds of adequate quality to be transformed into biofuels. However, this plant still presents limitations for its establishment as a commercial crop since it produces low seeds, which can be attributed to its low production of female flowers. This plant also presents multiple and asynchronous flowering periods as a consequence of the accession and of the climatic conditions, which implies that the fruits do not ripen synchronously, and therefore the harvests are constant, manual, and expensive. Knowing the mechanisms that regulate the flowering of J. curcas is important to improve its seed production. Therefore, current revision covers the analysis of genes involved in flowering to gain information on the pathways involved in floral transition and in the differentiation of the sexual organs of J. curcas.

We investigated the expression and functions of a transcription factor gene, RDD3. It displays sequence similarity to RDD1, which controls various nutrient ion accumulation and uptake in rice. The RDD3 protein was specifically localized to protoxylems and metaxylems in the vascular bundles. RDD3-overexpressing (RDD3-OX) plants increased the RDD3 protein levels early in the light period and improved NH₄⁺ and Mg²⁺ uptake and accumulation in the shoots. Furthermore, photosynthetic CO₂ assimilation and stomatal conductance in RDD3-OX plants were higher than in wild-type plants, although shoot dry weight was decreased in mature RDD3-OX plants. Subsequent microarray analysis indicated that the late embryogenesis abundant (LEA) protein genes associated with drought responses were upregulated in RDD3-OX plants, whereas WRKY transcription factor genes were downregulated despite participating in defenses against biotic and abiotic stresses. Examining drought stress tolerance indicated that RDD3-OX plants were more tolerant than wild-type plants. These results indicate that increased RDD3 protein levels early in the light period improve nitrogen and magnesium accumulation and drought stress tolerance in RDD3-OX plants.

Gene editing allows for precise editing and modification of specific target genes within an organism’s genome. The CRISPR/Cas9 technology has become the most widely used gene editing technique. Ornamental traits determine the aesthetic value of plants, and improving ornamental traits has become a research hotspot. The gene editing technology mediated by the CRISPR/Cas9 system has been widely applied in crop genetics and breeding, and there are increasing reports of its application in flowers. This article reviews specific cases of CRISPR/Cas9 technology in ornamental plants, summarizes its current application status and enormous potential in ornamental plants, and hopes to provide a reference for its better application in flower breeding.

India is one of the secondary centers of origin for both wild and domesticated bananas, with the north-eastern region holding the greatest repository. Therefore, the present study used three different molecular marker systems viz., inter simple sequence repeats (ISSR), inter-retrotransposon amplified polymorphism (IRAP), and start codon targeted (SCoT) polymorphism to analyze the genetic diversity among 17 cultivated varieties of the north-eastern region belonging to different genomic groups. The percent polymorphism was found to be 91.79, 86.78, and 82.35 in ISSR, IRAP, and SCoT markers respectively. ISSR had the highest values for all the marker parameters. However, IRAP outperformed SCoT and ISSRs by recording the highest values for effective number of alleles (N_e), Shannon index (I), and Nei’s (1973) gene diversity (H). The dendrogram obtained using ISSR, SCoT, and combined data had two major clusters and the clustering pattern was almost similar, but it differed slightly in IRAP markers. To learn more about the population structure and allelic diversity, model-based structural analysis was carried out in addition to phylogenetic analysis and principal component analysis (PCA). The structure analysis identified three subpopulations in ISSR, four in IRAP, and five in SCoT and combined marker data. The Q-value indicates that almost all the subpopulations are composed of varieties with and without admixture, thereby suggesting that more alleles are being shared among the varieties used in this study.

Maize is one of the three major food or feed crops in China. Bacillus subtilis protease like serine protease (SBT) is a serine proteolytic enzyme, which widely exists in various organisms and participates in biological growth and defense. However, SBT genes functions remained uncharacterized in growth and stress response in maize. Therefore, here we characterized the SBT gene family of maize. In this study, we identified 59 maize SBT genes (ZmSBTs), which were divided into 6 subfamilies through phylogenetic analysis. ZmSBTs are distributed unevenly on 10 chromosomes in Maize. As expected, ZmSBTs contained cis-acting elements for plant growth and defense. In addition, the transcriptome data of different maize tissues shows the dynamic differential expression of ZmSBTs in different tissues. We also predicted the interaction of ZmSBT1.7 and ZmSBT2.5 specifically expressed in meiosis_tassels with other maize proteins. We revealed that the ZmSBT1.2 is specifically expressed in seeds with other maize proteins. This study provided valuable information about maize SBT gene family and clarified the possible biological functions of ZmSBT1.7, ZmSBT2.5, and ZmSBT1.2. The identified candidate genes could be used to breed higher-yielding Maize cultivars to feed the world population.

Iron (Fe) is an essential mineral element, and its deficiency in soil largely affects crop productivity. In plants, the molecular mechanisms underlying the genetic regulation of Fe-deficiency responses pinpointing microRNA (miRNA)-mediated regulation of Fe-deficiency response and its regulatory network are largely unaddressed. In the present study, we performed a small RNA-targeted whole-genome transcriptome analysis from hexaploid wheat and identified small RNAs (sRNAs) responding to Fe deficiency. Detailed analysis identified 105 differentially expressed miRNAs corresponding to Fe-deficiency response, and nine miRNAs were found to be novel in this study. Interestingly, tissue-specific regulation of Fe-deficiency response also participates through miRNA-mediated regulation. We identified 17 shoot-specific miRNAs and 18 root-specific miRNAs with altered expression. We validated the tissue specificity of these miRNAs by stem-loop quantitative RT-PCR that confirmed a temporal regulation. Furthermore, an attempt was made to predict their targets to speculate their participation in Fe-deficiency response. The miRNA target prediction analysis suggested a few major target genes, such as multicopper oxidases, E3 ubiquitin ligases, GRAS family, and WRKY transcription factors; those are previously known to play key roles in Fe homeostasis. The first preliminary information generated here will classify the repository of wheat miRNAs (with few novel miRNAs) for their role in Fe-deficiency response. Our work provides insights into miRNA-mediated regulatory pathways during Fe deficiency.

Identification of the source of genetic variation in the large and complex genome of sugarcane has been comparatively less explored through next-generation sequencing tools. In this study, RNA-seq libraries of two extreme bulks from a segregating full-sib population and its parents were used to identify highly significant, alternate splicing (AS) events and premature stop codons (PMC) associated with early sucrose accumulation. An important differential AS event was identified within the β-subunit of pyrophosphate-fructose 6-phosphate 1-phosphotransferase (PFP) which plays a key role in carbon partitioning in sugarcane. Premature stop codons that could result in truncated proteins were also detected in genes coding for aquaporin, aldolase, cytochrome C-oxidase, ribophorin and plant plasma membrane intrinsic proteins. A major proportion of these AS events and premature stop codons was validated for their differential enrichment in an independent set of sugarcane varieties having high and low sucrose content. The results provide useful insights into the role of putative AS events and premature stop codons which could be useful as candidate markers in marker-assisted breeding for developing high sugar varieties in sugarcane.