Current Plant Biology最新文献

The use of microbes capable of beneficially interacting with plants is essential for advancing climate-smart agriculture. This approach aims to reduce chemical use while simultaneously enhancing crop productivity. This implies efforts to optimize the criteria for selecting potential plant growth promoters (PGPs), focusing also on yeasts, only recently investigated for their PGP potential. The present study employed a set of Ascomycetes and Basidiomycetes yeasts to test their PGP properties on zucchini (Cucurbita pepo L.), chosen as a fast-growing plant with a vast economical interest. Yeasts were tested alone and as consortium. Seed inoculation with yeasts boosted the early phase of growth of the zucchini plants, primarily affecting the root development. Three strains belonging to the species Schwanniomyces etchellsii, Zygotorulaspora florentina and Holtermanniella festucosa induced a strong and significant enhancement of weight and length of both epi- and hypogeal parts of the plant. Furthermore, the presence of yeasts induced strain-specific modulations in the biochemical profiles of soil, primarily detected in the rhizosphere. This suggests an active interaction between the roots and the inoculated yeast cultures.

Although a major grain crop, maize is a deficit in Lysine (Lys), which is one of the essential amino acids (EAAs). Several attempts of molecular biology, conventional breeding, marker-assisted breeding, and single/multiple transgenesis have significantly increased Lys content in maize seed. However, till now, no commercial high-Lys maize for human consumption is available in the global market. Therefore, alternative strategies are needed that be adopted over the above-mentioned techniques to develop high-Lys maize. In addition to microbes, circuit-enabled programming-based synthetic biology has significantly improved the desired characteristics of crops including maize as synthetic mini chromosomes have already been built and transferred into maize. The above technology is advantageous as it is a precisely guided artificially controlled system that acts better in addition to the natural system or over the natural system. During the designing and programming of the synthetic genetic circuit for high-Lys maize, a deep understanding of natural Lys biosynthesis pathways, Lys metabolism, metabolic flux, metabolic interconnections, transporters, and transcription factor, post-translational protein regulation are needed. Hence, major genes in aspartate (Asp) pathway, like dihydrodipicolinate synthase (DHPS), aspartate kinase (AK), Lys-ketoglutarate reductase/saccharopine dehydrogenase (LKR/SDH) should be critically analyzed in maize before incorporating these into high-Lys synthetic genetic circuit. Indeed, a prototype of the synthetic high-Lys genetic circuits must have a synthetic switch for precise regulation of multiplex gene expression, memory circuits, synthetic boolean logic gates, and synthetic intercellular communication systems. For proper transformation of the synthetic high-Lys genetic circuit, the landing pad should be specific. Then, precise monitoring and remote regulation of the circuit over several generations might be done to obtain stable programmed high-Lys synthetic maize. Therefore, considering the current advancement of single/multiple transgenesis, conventional breeding, marker-assisted breeding that successfully increased maize Lys, precise programming-based synthetic genetic circuits should be designed for getting high-Lys maize following the mechanism of how the synthetic genetic circuits would work in the maize genome and its remote control. These need deep understanding in maize biology, integration of previously published transgenesis for high-Lys maize, in silico, in vitro and in vivo experiments for successful development of programming-based synthetic genetic circuit enabled high-Lys maize.

Members of bZIP gene family play crucial roles in various biological processes, including plant growth and development, stress response, and light signal transduction. Despite their significance, there is limited information on the function of the bZIP gene family in peanuts. In this investigation, we identified a total of 99 bZIP gene family members in the peanut genome, distributed across 20 chromosomes. Phylogenetic tree analysis categorized the peanut bZIP gene family into 10 groups, with groups I, D, A and S being the most widely distributed. Transcriptome analysis of peanut pods revealed that 10 bZIP family genes exhibited significant induction in response to light, suggesting their potential involvement in light signal transduction in peanuts. Within the peanut bZIP family, group H comprises six genes AhbZIP13, AhbZIP63, AhbZIP39, AhbZIP44, AhbZIP91 and AhbZIP96. Particularly, the expression of the AhbZIP63 (AhHYH) gene significantly increased under light induction, indicating a pivotal role in light signal transduction. DAP-seq analysis of AhbZIP63 (AhHYH) demonstrated its direct regulation of genes associated with UV response and cellular response to nutrient levels.

Iron is an essential plant nutrient, and a continuous supply of it is required as it is a key factor in various metabolic processes, including photosynthesis, chlorophyll synthesis, and respiration. Various transcription factors are known to regulate iron homeostasis in plants, and the bHLH transcription factor family is one of them. The StbHLH47 is a homologue of the Arabidopsis POPEYE (PYE), which is known to repress iron homeostasis-related genes in Arabidopsis. Potato is the most consumed vegetable in the world and is low in iron content. We have generated CRISPR/Cas9-edited StbHLH47 lines and performed a detailed analysis of these lines. The analysis revealed that the roots of StbHLH47 edited lines have decreased ferric chelate reductase (FCR) activity compared to the roots of the wild-type (WT) plant. We also observed that CRISPR/Cas9 edited lines have fewer trichomes when compared to the WT plant. The expression of genes associated with iron homeostasis was also measured. Compared to the control, the expression of StbHLH47 was downregulated in the edited lines, while the expression of StNAS4, StOPT3, and StFRO3 was upregulated. This suggests the negative regulation of StbHLH47 in modulating iron. The iron content was also quantified using inductively coupled plasma mass spectrometry (ICP-MS) and found to be increased in the generated transgenic lines when compared to WT plants. Overall, this study reveals that StbHLH47 negatively regulates the expression of iron homeostasis-related genes. StbHLH47 edited lines exhibited decreased FCR activity, changes in phenotype, and increased iron content in the potato plants.

Key message

This study provides novel insight into the role of StbHLH47 in modulating iron content in Solanum tuberosum and controlling the expression of various iron homeostasis-related genes.

Sakuranetin, a flavonoid phytoalexin in rice, plays a crucial role in defense against pathogen infection. While MYB-type transcription factors are well-known to regulate plant growth, development, secondary metabolism, and adaptation to environmental stresses, the function of rice MYB-related transcription factors in sakuranetin biosynthesis and sakuranetin-mediated defense remains unclear. In this study, we identified and characterized OsMYB1R, a novel single repeat MYB transcription factor that acts as a transcriptional activator in sakuranetin biosynthesis. Protein-DNA binding and activation assays revealed that OsMYB1R directly regulates the gene promoter of OsNOMT, a key enzyme in sakuranetin synthesis. Molecular analyses and infection studies using OsMYB1R-overexpressing (OsMYB1R-OE) and OsMYB1R-knockout (Osmyb1r, generated using CRISPR/Cas9) plants demonstrated that OsMYB1R increases sakuranetin production and decreases Magnaporthe oryzae infection by transcriptionally regulating OsNOMT expression. This finding indicates a positive regulation of sakuranetin biosynthesis and antifungal resistance by the OsMYB1R-OsNOMT crosstalk. Interestingly, the alteration of OsMYB1R expression did not affect yield-related agronomic traits. Our results reveal a novel and positive role of 1R-MYB in secondary metabolite biosynthesis and pathogen defense, suggesting that OsMYB1R is a potential gene for effectively enhancing rice resistance without compromising yield.

The NAC (NAM, ATAF and CUC) family is one of the largest transcription factor (TF) families in plant that are involved in the regulatory mechanisms of plant growth and development as well as responses to abiotic stresses. However, the underlying molecular mechanism of drought-responsive NAC family members in soybean still remains inexplicit. In this study, a total of 179 GmNAC genes were identified in the soybean genome. We discovered that the majority of GmNAC members have more than three exons and share a gene and motif structure that is mostly conserved at the N-terminus. Phylogenetic analysis suggested that soybean GmNAC proteins were divided into 10 separate groups. The analysis of cis-elements highlighted the potential role of GmNAC genes in various hormonal and defense related activities. In addition, most of the GmNAC genes showed notable expression in roots and leaves, suggesting their likely role in abiotic stress adaptation. The overexpression of GmNAC3-OE in Arabidopsis increased tolerance to drought stress. Similarly, the GmNAC3-OE plants displayed better survival rates, root length and antioxidant activities. Enhanced expression of stress specific genes in GmNAC3-OE was also recorded. Our findings revealed the potential role of GmNAC3 gene role in regulating soybean response to drought stress and could be used as a potential marker to generate stress resilient plants.

Salinity stress is considered as one of the major detrimental stresses for reducing plant growth and crop productivity. Hence, concerted efforts are going on to develop sustainable solutions for reducing salinity-induced negative effects on crop productivity. Given this, the present study evaluated the potential of ash gourd extract (AGE; 0.9 µg/mL) for ameliorating NaCl (100 mM) stress in rice, which is one of the major staple food crops worldwide. The differential phenotyping revealed growth reduction under NaCl treatment, as indicated by 0.27- and 0.36-fold decrease in survival and whole-seedling biomass, respectively, compared with those of control. In contrast, 24 h pre-treatment with AGE before NaCl exposure (AGE24h+NaCl) improved these growth attributes by 1.29- and 1.70-fold, respectively, compared with those of NaCl treatment. The differential phenotype of AGE was associated with its inherent ability to scavenge reactive oxygen species, which was equivalent to 0.08-fold of ascorbic acid. The higher accumulation of superoxide radicals and upregulated expression of stress marker genes including OsTSPO, OsCBS, OsHKT1;5, and OsNHX1 under AGE24h treatment also suggested AGE mediated priming effect. Under AGE24h+NaCl, the expression levels of these stress markers were either maintained or their extent of upregulation was further enhanced. In addition, the coordinated activation of antioxidant machinery and reduced Na-accumulation further supported stress amelioration under AGE24h+NaCl treatment. GC-MS-based metabolomics highlighted fatty acids, malic acid, myo-inositol, allose, trehalose, and L-oxoproline, as key metabolites, associated with AGE-mediated amelioration of NaCl stress. The foliar application of AGE increased seed yield and 1000 seed weight by 1.13- and 1.06-fold, respectively, compared with those of NaCl, validating its agronomic feasibility. Thus, the results highlighted the application of AGE, as a “green” bioregulator for ameliorating NaCl stress conditions in rice.

The biotrophic fungus Hemileia vastatrix is the pathogen responsible for coffee leaf rust, a devastating disease in several coffee-producing countries. Despite the importance of studying the interaction between Coffea and H. vastatrix, a more comprehensive understanding of the mechanisms involved in this pathosystem is necessary. The role of eight candidate genes was analyzed aiming at identifying and validating new important coffee resistance genes and understanding their interaction with H. vastatrix. These genes were identified in the most important sources of coffee resistance, the Híbrido de Timor CIFC 832/2 and CIFC 832/1. Previous works found six resistance genes and, in our research, other two new genes were identified in BAC clones and validated by RT-qPCR during compatible and incompatible interactions between Coffea and H. vastatrix. An interactome approach was performed using Coffea-H. vastatrix and Coffea-Coffea proteins to better understand the biological process and the interaction of the host-pathogen. Two networks of interactions from the compiled data were built focused on candidate genes associated with pre-haustorial resistance (12 and 24 h.a.i) in coffee plants against the pathogen. The results showed, for the first time, differentially expressed proteins (DEPs) positively regulated in the incompatible interaction Coffea-H. vastatrix. These coffee proteins interact with each other and with secreted and/or transmembrane pathogen proteins. The obtained results also show that DEPs found are involved in important plant defense pathways such as pathways associated with the response to wounds, signaling, regulation of the innate immune response and the transmembrane receptor protein serine/threonine kinase pathway. The present work shows the involvement of genes in both pathogen recognition and signaling cascades, which act in pre-haustorial defense mechanisms of HdT coffee. Therefore, the candidate genes analyzed, together with the biological processes elucidated, have the potential to contribute to the development of new control strategies against the fungus H. vastatrix within coffee breeding programs aiming to develop cultivars with durable resistance.

Pollen analysis is essential for discerning the botanical and geographical origins of honey, ensuring authenticity, quality, and commercial value. The Sahara Desert in Algeria boasts unique floral diversity, with its melliferous plant species contributing to regional honey production. Nevertheless, a lack of comprehensive information on the pollen characteristics of these plants impedes precise identification of the geographical and botanical origins of Saharan honeys. Given the importance of understanding honey origin for quality assurance, this study addresses the challenge posed by the scarcity of melissopalynological data in the Sahara Desert. By offering a detailed characterization of Sahara Desert melliferous plant pollen, the research contributes valuable insights to the broader field of honey authentication and underscores its significance in the industry. Therefore, this study was conducted to characterize the pollen of melliferous plants in the Sahara Desert, which is essential for establishing a database that can aid in the determination of honey origins, protect against fraudulent activities, and support conservation efforts. This study aimed at the characterization of pollen of spontaneous melliferous plants from the Sahara Desert of Algeria to facilitate the determination of the geographical and botanical origin of honeys produced in this region. In three regions (Ghardaïa, Touggourt and Ouargla), pollen morphological features namely: polar length (PL) and equatorial diameter (ED), size, shape, apertures and exine ornamentations of 19 native plant species were studied through the sampling of ten flowers per plant and ten pollen grains per flower for each species (n = 3800 measurements). The surveyed plant species showed that medium-sized pollens (25–50 µm) were the most dominant (73.34 %), followed by slam-sized pollens (21.18 %), with the smallest size observed in Tetraena alba (PL = 18.98 ± 4.82 μm, ED = 18.95 ± 5.06 μm) and the largest size measured in Faidherbia albida (PL = 58.03 ± 4.65 µm, ED = 57.46 ± 4.70 μm). The most frequent forms of pollen in different species were prolate-spheroidal (32.68 %) and oblate-spheroidal (26.53 %). Diverse types of exine ornamentations and were detected at the pollen unit level with a dominance of reticulate (57.89 %). Tricolporate (42.11 %) and tricolpate (31.58 %) were the dominate pollen apertures. This study characterized pollen from Sahara Desert melliferous plants, which can aid honey origin determination, ensuring quality and supporting conservation, with implications in authentication, protection, and preservation of floral resources for sustained honey production.