BMC Plant Biology最新文献

Background: The translocation of photoassimilates is a critical process that links the source and sink in plants, playing an irreplaceable role in maintaining source-sink balance, ensuring plant growth and development, and the formation of yield. Nevertheless, the mechanisms underlying the translocation of photosynthetic products in macroalgae are yet to be fully understood. The purpose of this study is to reveal the role of endocytosis in the translocation of photosynthetic products in the marine red alga Gracilariopsis lemaneiformis by investigating the uptake of photosynthetic products by endocytosis and the impact of endocytic activity on cellular ultrastructure, photosynthesis, and growth.

Results: This study discovered that the endocytic activity in non-epidermal cells (NEC, sink cells) of G. lemaneiformis is significantly higher than that in epidermal cells (EC, source cells). NEC is capable of internalizing a greater amount of extracellular carbohydrates, such as sucrose, via endocytosis compared to EC. Further inhibition of endocytic activity in G. lemaneiformis using EIPA resulted in a significant reduction in the content of floridean starch within NEC, whereas the decrease in floridean starch content in EC was not statistically significant. Inhibition of endocytic activity led to an initial decline in photosynthetic efficiency of algal thalli within a few hours, which was followed by an increase as inhibition duration extended, yet the growth rate of the thalli remained substantially suppressed.

Conclusions: These findings indicate that endocytosis in G. lemaneiformis plays a role in regulating the cellular uptake of extracellular photoassimilates, which in turn influences the storage substances in sink cells and the overall growth and development of the algae. This study sheds new light on the regulatory mechanisms governing photoassimilate translocation in macroalgae.

Background: Salinity is a major threat to rice growth and productivity. Utilizing wild rice-derived genes and biostimulants with high growth promoting- and stress-alleviating potential can significantly improve salinity tolerance in cultivated rice. Herein, we investigated the vegetative growth and physiological responses of Giza 177 (Oryza sativa, salinity sensitive, high-yielding cultivar) and a promising introgression salt tolerant line (sativa/glaberrima; SG 65) from a population of Giza 177 × African rice (Oryza glaberrima) under low (2.75 mS/cm) and high (5.5 mS/cm) salinity stress. The possible ameliorative effects of priming rice seeds in moringa leaf extract (MLE) on these responses were also tested.

Results: The two salinity levels induced differential reduction in plant growth in both cultivars. In the MLE-unprimed plants, salinity induced 34-54% and 30-45% reductions in biomass accumulation in Giza 177 and SG 65, respectively. These responses were associated with significant differential reductions in relative water content, chlorophylls, carotenoids, and gas exchange parameters (transpiration rate, net photosynthetic rate, stomatal conductance, and intercellular CO₂ concentration), ascorbic acid, and total protein. Conversely, salinity induced the accumulation of H₂O₂, malondialdehyde, proline, carbohydrate fractions, and membrane injury. MLE treatment mitigated the above salinity-induced adverse effects in both cultivars via reducing the salt-induced oxidative stress through the induction of non-enzymic (total phenols, and flavonoids) and enzymic antioxidants including ascorbate peroxidase, catalase, peroxidase, and polyphenol oxidase in both cultivars. SG 65 plants exhibited consistently higher salt tolerance and responsiveness to MLE than Giza 177.

Conclusions: This study reports significant differences in an array of critical physiological and biochemical indices that underpin the divergent responses between the two salinized cultivars. It demonstrates the potential of African rice-derived genomic fragments and MLE priming in mitigating salinity stress, highlighting their use as a sustainable strategy for increasing rice production in salt-affected soils.

The present study documented the effect of bio-organics in legume intercropped strawberry cv. Camarosa during the years 2022 and 2023. Bio-organic fertilizer inputs included were Jeevamrit (JV), Ghan-Jeevamrit (GJ) and Azolla. Coriander-Strawberry-Fenugreek as intercropping system was adopted. The treatments comprised were T₁: GJ at 100 g/m² + JV at 10% +Azolla at 200 g/plant, T₂: GJ at 150 g/m² + JV at 10% +Azolla at 200 g/plant, T₃: GJ at 100 g/m² + JV at 20% +Azolla at 200 g/plant, T₄: GJ at 150 g/m² + JV at 20% +Azolla at 200 g/plant, T₅: GJ at 100 g/m² + JV at 10% +Azolla at 250 g/plant, T₆: GJ at 150 g/m² + JV at 10% +Azolla at 250 g/plant, T₇: GJ at 100 g/m² + JV at 20% +Azolla at 250 g/plant, T₈: GJ at 150 g/m² + JV at 20% +Azolla at 250 g/plant, T₉: GJ at 150 g/m² + JV at 20% as per SPNF, T₁₀: Farmyard manure (100% N basis) and T₁₁: Recommended dose of N: P:K (80:40:40 kg/ha) as control. Application of bio-stimulants at 50 g/plant and AM fungi @ 20 g/ plant was applied uniformly in treatments T₁-T₈. One month after transplanting, T₃ showed positive influence on vegetative growth traits of strawberry plantlets. Minimum number of days taken to flower, maximum duration of flowering (142) and number of flowers (51) were also recorded. This treatment application also observed maximum fruit yield (677.93 g/ plant) and yield efficiency (7.91 g/cm² of leaf area) compared to all other bio-organic combinations applied. Post harvest soil chemical indicators were also significantly influenced except pH and electrical conductivity compared to FYM (100% N equivalence) and Recommended dose of fertilizers (RDF) of NPK (80:40:40 kg/ha). Microbial biomass in terms of total bacteria, soil fungi, actinobacterial count, phosphorous solubilizing bacteria, AM spore population, Azotobacter count and Soil enzymatic activity of phosphatase and dehydrogenases showed a steady rise after application of GJ @ 100 g/m² + JV @ 20% + Azolla @ 200 g/plant. In addition, overall increase of the yield of coriander and fenugreek compared to FYM (100% N equivalence) and RDF of NPK (80:40:40 kg/ha) was recorded. The positive influence both on leaf and fruit NPK contents were also recorded when plantlets were supplemented with GJ @100 g/m² + JV@ 20% + Azolla @ 200 g/plant. This study inferred that application of bio-organic inputs sources which can boost up cropping behavior, post harvest soil indicators, native microbial properties and enzymatic activity in rhizosphere, and thus can have the potential to improve crop resilience and soil productivity on sustainable basis.

Background: Munkoyo, a non-alcoholic fermented beverage, is traditionally prepared in Zambia and neighbouring countries using cooked grains and the uncooked roots of wild plant species, collectively called 'Munkoyo' plants. The drink, valued for its refreshing taste and nutritional contribution, is made using roots of several wild plant species resulting in variations in the taste and quality of the beverage. However, comprehensive information on the specific plant species used in different regions of Zambia, as well as their occurrence in terms of habitat and soil type, is missing. This gap limits our understanding of the factors contributing to Munkoyo's heterogeneity. The present study sought to identify the Zambian plant species used as an inoculum in Munkoyo fermentation and to characterize the soil in which they occur.

Results: Plant and soil samples were collected from four districts in Zambia known for Munkoyo production. Using morphological taxonomy, three Fabaceae species were identified as commonly used Munkoyo plants: Rhynchosia insignis (O.Hoffm.) R.E.Fr., Rhynchosia heterophylla Hauman, and Eminia holubii (Hemsl.) Taub. Root colour differed among these species, with the Rhynchosia species having yellowish roots and E. holubii having whitish roots. To validate their identification, we evaluated three DNA barcoding markers (matK, rbcL, and ITS2) for species discrimination. All markers showed 100% PCR amplification and sequencing success rates, with ITS2 displaying the highest genetic variability and species-level resolution. Phylogenetic analyses further confirmed ITS2 as the most effective marker. Validation using samples from a fifth district reaffirmed ITS2's suitability for species-level discrimination. Soil analysis revealed significant associations between soil texture and plant occurrence: R. insignis and E. holubii were prevalent in sandy soils, while R. heterophylla was more prevalent in soils with lower sand content.

Conclusions: This study identified three common Munkoyo plant species and demonstrated ITS2 as a robust DNA barcode for their identification. It also established the influence of soil texture on the distribution of these plants, contributing to the understanding of Munkoyo production's biological and environmental determinants.

Background: Allopolyploid plants are valuable for plant breeding because they have the advantage of polyploidization and hybridization, such as increased vigor and adaptability. Although biparental triploid endosperms have the potential to be used to produce allotriploid plants, the approach remains largely unexplored. Therefore, this study aimed to produce allotriploid plants from the endosperms of interspecific crosses between Haemanthus pauculifolius and H. albiflos.

Results: Precisely identified embryo and endosperm pairs were used. Embryos were grown on half-strength Murashige and Skoog (MS) medium, and endosperms from interspecific crossing were cultured to induce callus formation and shoot regeneration, which then developed into plantlets. MS medium supplemented with 4-amino-3,5,6-trichloropicolinic acid (picloram) and 6-benzylaminopurine (BAP), or 2,4-dichloro phenoxy acetic acid (2,4-D) and BAP were used for callus induction, and callus formation rates were measured. Flow cytometry, karyotyping, and Sanger sequencing of the nuclear internal transcribed spacer (ITS) region, chloroplast (trnL-trnF region, matK gene), and mitochondrial (nad1 gene) DNA were performed on plantlets derived from embryos and endosperms, along with their parental plants. In this study, a total of 18 pairs of diploid and triploid plantlets were obtained from the embryo and endosperm, respectively. Callus formation rates were significantly higher on media with picloram and BAP compared to 2,4-D and BAP. ITS sequencing and karyotype analyses detected that all the 16 pairs of plantlets analyzed were hybrids, indicating that most endosperm-derived plantlets were allotriploid with a parental chromosome ratio of 2:1 (maternal: paternal). In addition, chloroplast DNA sequencing revealed maternal inheritance in the endosperm-derived plantlets, consistent with embryo-derived plantlets.

Conclusions: This study is the first to demonstrate the production of allotriploid hybrid plants through endosperm culture using seeds from interspecific crosses, as supported by cellular and genetic analyses. Additionally, the study established a novel system for simultaneously producing diploid and allotriploid hybrids from a single seed, providing valuable materials to study the effects of polyploidization and hybridization in allopolyploid plants. These findings contribute to plant breeding strategies and advance our understanding of hybridization, polyploidization, and allopolyploid plant development.

Developing F3 transgenic segregants has significant potential to improve cayenne pepper varieties. However, current evaluation methods are often inconsistent and inaccurate, hindering the identification of effective traits. Traditional approaches only focus on a few aspects, thus not covering the full potential performance of the genotype. Utilizing morphometric image processing and categorical parameter assessment can fill the gap of traditional approaches to improving accuracy and objectivity in evaluation. In addition, environmental factors affecting the evaluation process are not adequately considered, making the results unreliable. Therefore, a systematic evaluation framework integrating morphometric analysis, categorical assessment, and environmental correction is essential for optimizing F3 cayenne transgressive segregants. The study aims to develop a synchronized assessment and selection approach based on agronomic, fruit morphometric, and categorical traits in evaluating F3 cayenne transgressive segregants. This research was designed with a randomized completed block design with 16 transgressive segregant genotypes and three check varieties. Each genotype was repeated three times, resulting in 57 experimental units. Based on the results of this study, quantitative and categorical indices could be used to selectively and systematically evaluate potential transgressive segregants in F3 cayenne peppers. The quantitative index is formed from outcome selection criteria, number of productive branches, area, and major axes weighted through an unbiased linear estimation approach, heritability, and best path analysis. Seven genotypes demonstrated superior transgressive performance based on quantitative indices, with G10.9.2, G10.7.1, and G6.8.5 excelling in both agronomic traits and categorical evaluations. These lines can be recommended for yield evaluation and hybrid cross-parents.

Background: The structure of chloroplast genomes (cpDNAs) in Fabaceae (Fab.) has undergone significant evolutionary modifications. Within the Papilionoideae (Pap.), the emergence of the Inverted Repeat-Lacking Clade (IRLC) represents a major genomic alteration. However, the molecular evolution and phylogenetic relationships within Pap. remain poorly resolved due to limited molecular data and incomplete research, highlighting the need for systematic investigation.

Purpose: This study presents an in-depth analysis of the cpDNAs within the Pap., with the aim of unraveling the molecular evolution and phylogenetic interconnections among its species.

Methods: Complete cpDNAs of 18 Pap. species were sequenced using the Illumina Novaseq 6000 platform, followed by assembly and annotation. Comparative genomic analyses were conducted to elucidate structural variations and phylogenetic relationships.

Results: The research has uncovered significant differences in the structure and characteristics of the cpDNAs within the Pap.. The lengths of the cpDNAs of 18 species range from 121,190 bp to 158,539 bp, and they contain between 107 and 112 unique genes. Five species, namely Desmodium elegans and Indigofera bracteata, exhibit a typical quadripartite structure, while thirteen species from genera such as Astragalus (Ast.), Hedysarum (Hed.), and Caragana (Car.) are grouped within the Inverted Repeat-Lacking Clade (IRLC). Genetic characteristic analysis revealed a plentiful presence of SSR loci, with single-nucleotide repeats and dinucleotide (A/T) repeats being the most predominant. Notably, the cpDNAs of five species including D. elegans have experienced significant rearrangements. For example, an inversion of approximately 23 kilobase (kb) pairs was observed in Pueraria peduncularis and Sophora moorcroftiana. These species exhibit pronounced differences in their non-coding regions. Comparative genomic variations at cpDNA sites were identified. Moreover, by using D. elegans as a reference, six genes (ycf4, clpP, ycf1, trnI-GAU, accD, rpl32) displayed high nucleotide polymorphism (Pi > 0.1), and the Ka/Ks ratio for all protein-coding genes was determined to be less than 1. The topological structure of the constructed phylogenetic tree of 85 species was basically consistent with that of Pap.. Seven main clades were formed and relatively high bootstrap values were exhibited, further clarifying the evolutionary relationships among them.

Conclusion: This study provides novel insights into the molecular evolution and phylogeny of Pap., offering a foundational resource for future taxonomic and evolutionary research.

The accurate estimation of regional crop yields holds significant importance for optimizing subsequent resource allocation and maximizing economic returns in agriculture. Crop yield can be effectively estimated by assessing the overall growth status through long-term remote sensing observations. However, most previous studies have relied on remote sensing data from one or a few periods for yield estimation, thus lacking a comprehensive description of entire crop growth. Furthermore, past algorithms have not considered their applicability across different observational scales (e.g., unmanned aerial vehicle (UAV)- and satellite-observed). Considering this, we extracted four maize growth process parameters using Leaf Area Index (LAI) obtained from UAV (equipped with multispectral sensor, centimeter-level) and satellite (MODIS, 1 km) observations: PP_a (representing the duration of the crop growth period), PP_b (representing the peak growth stage of the crop), PP_c (representing the initial state of the crop), and LAImax (maximum LAI). These parameters were used to construct a maize yield estimation model applicable at both regional and field scales. The results indicate that the four process parameters extracted in this study can accurately estimate crop yields, with rRMSE = 14.08% at the field-scale and rRMSE = 17.75% at the regional-scale. Among these parameters, PP_a, representing the duration of the crop growth period, and the maximum LAI, are the parameters that individually contribute the most to the estimation accuracy. Moreover, the proposed method exhibited good spatial applicability (field-scale: Moran Index (MI) = -0.18; regional-scale: MI = 0.19). In conclusion, the parameters describing maize growth process derived from long-term-series observations can effectively estimate maize yield across different observation scales. This method not only facilitates the optimization of agronomic practices based on UAV observations but also supports the decision of regional agricultural policies based on satellite observations. Furthermore, crop yield estimation utilizing process-based parameters provides a new perspective for related studies.

Background: Gymnocarpos przewalskii Bunge ex Maxim. (G. przewalskii) is an endangered xerophytic shrub that plays a crucial role as a source of forage in the Alxa Desert. However, there is limited understanding regarding the forage quality of G. przewalskii and its response to drought. This study aimed to evaluate the forage quality of G. przewalskii and investigate the physiological and transcriptomic changes in G. przewalskii response to drought stress.

Results: The ash, fat, crude protein, lignin, crude fiber, acid detergent fiber, and neutral detergent fiber contents in G. przewalskii twigs were 10.61%, 1.85%, 5.68%, 7.08%, 21.23%, 42.16%, and 58.42%, respectively. In contrast, these ingredients in its leaves were 20.39%, 0.92%, 11.96%, 2.40%, 17.51%, 14.29% and 20.26%, respectively. Osmotic stress led to a reduction in chlorophyll levels and an increase in malondialdehyde content. Levels of hydrogen peroxide and oxygen free radicals remained relatively stable under osmotic stress. The proline content, SOD and CAT activities, and ·OH scavenging capacity were enhanced in G. przewalskii under osmotic stress. RNA-sequencing of G. przewalskii generated 44.51 Gb clean reads, which were assembled into 102,191 Unigenes and 30,809 Unigenes were successfully annotated. Comparative analysis identified 3,015 differentially expressed genes under osmotic stress. There were 2,134 and 1,739 DEGs enriched in 47 GO secondary categories and 129 KEGG pathways, respectively. 2 up-regulated DEGs were annotated to P5CS, a key enzyme in the biosynthesis of proline. 32 DEGs were annotated to various antioxidases and antioxidants. 81 DEGs were annotated to 8 plant hormone signaling pathways, in which the auxin and ABA signaling pathways exhibited dominant enrichment. 150 DEGs were annotated to 35 transcription factor families with the abundant enrichment of TF families containing WRKY, bZIP, ERF, bHLH, MYB, and NAC.

Conclusions: High forage quality and drought stress tolerance were observed in G. przewalskii. In response to drought stress, G. przewalskii orchestrates reactive oxygen species scavenging, proline biosynthesis, and other intricate physiological processes, with substantial contributions from plant hormones and transcription factors. This study provides new insights into the forage quality and the mechanisms involved in drought adaptation of G. przewalskii, offering a foundation for its conservation and sustainable utilization.