BMC Plant Biology最新文献

Background: This study examines the effects of various complementary light spectra on the growth, development, antioxidant activity, and nutrient absorption in strawberry plants under stress conditions. Light-emitting diodes (LEDs) were used to provide specific wavelengths, including monochromatic blue (460 nm), monochromatic red (660 nm), a dichromatic mix of blue and red (1:3 ratio), full-spectrum white light (400-700 nm), and ambient light as a control (no LED treatment). The stress treatments applied were: control (no stress), salinity (80 mM NaCl), alkalinity (40 mM NaHCO₃), and a combined salinity/alkalinity condition.

Results: Our results indicated that complementary light spectra, especially red and blue/red, helped mitigate the adverse effects of stress on plant growth and development. These spectra improved plant tolerance by enhancing the activity of polyphenol oxidase and peroxidase enzymes and increasing starch accumulation in the leaves. Furthermore, under stress conditions, red and blue-red light significantly boosted fruit anthocyanin levels. Although stress elevated antioxidant activity, supplementary light reduced this activity by alleviating stress compared to ambient light. While stress led to increased Na and Cl ion concentrations in leaves, treatments with blue, red, and blue-red light minimized these harmful effects and promoted the absorption of beneficial ions such as K, Mg, Fe, and Cu.

Conclusions: Adjusting light quality significantly influences the morphology and physiology of strawberry plants, underscoring the role of specific light spectra in promoting optimal growth under stress conditions.

Clinical trial number: Not applicable.

Background: Bacterial wilt (BW), caused by Ralstonia solanacearum (Ral), results in substantial yield losses in pepper crops. Developing resistant pepper varieties through breeding is the most effective strategy for managing BW. To achieve this, a thorough understanding of the genetic information connected with resistance traits is essential. Despite identifying three major QTLs for bacterial wilt resistance in pepper, Bw1 on chromosome 8, qRRs-10.1 on chromosome 10, and pBWR-1 on chromosome 1, the genetic information of related BW pepper varieties has not been sufficiently studied. Here, we resequenced two pepper inbred lines, C. annuum 'MC4' (resistant) and C. annuum 'Subicho' (susceptible), and analyzed genomic variations through SNPs and Indels to identify candidate genes for BW resistance.

Results: An average of 139.5 Gb was generated among the two cultivars, with coverage ranging from 44.94X to 46.13X. A total of 8,815,889 SNPs was obtained between 'MC4' and 'Subicho'. Among them, 31,190 (0.35%) were non-synonymous SNPs (nsSNPs) corresponding to 10,926 genes, and these genes were assigned to 142 Gene Ontology (GO) terms across the two cultivars. We focused on three known BW QTL regions by identifying genes with sequence variants through gene set enrichment analysis and securing those belonging to high significant GO terms. Additionally, we found 310 NLR genes with nsSNP variants between 'MC4' (R) and 'Subicho' (S) within these regions. Also, we performed an Indel analysis on these genes. By integrating all this data, we identified eight candidate BW resistance genes, including two NLR genes with nsSNPs variations in qRRs-10.1 on chromosome 10.

Conclusion: We identified genomic variations in the form of SNPs and Indels by re-sequencing two pepper cultivars with contrasting traits for bacterial wilt. Specifically, the four genes associated with pBWR-1 and Bw1 that exhibit both nsSNP and Indel variations simultaneously in 'Subicho', along with the two NLR genes linked to qRRs-10.1, which are known for their direct involvement in immune responses, are identified as most likely BW resistance genes. These variants in leading candidate genes associated with BW resistance can be used as important markers for breeding pepper varieties.

Background: Rice ECQ (eating and cooking quality) is an important determinant of rice consumption and market expansion. Therefore, improvement of ECQ is one of the primary goals in rice breeding. However, ECQ-related quantitative trait loci (QTL) have not yet been fully revealed. The present study aimed to identify a major effect QTL for rice taste, an important component of ECQ via genotyping-by-sequencing, to reveal the associated molecular mechanisms, and to predict key candidate genes.

Results: A population of F₉ recombinant inbred lines resulting from a cross between R668 (national standard of high-quality third class) and R838 (common edible rice) was used to construct a high-density genetic map (2,295.062 cM). The map comprises 639,504 markers distributed on 12 linkage elements with an average genetic distance of 0.004 cM. We detected a major taste-related QTL, qECQ8, which explained 41.4% of phenotypic variance and had LOD values of 4.42-7.73. Using a five-generation NIL population from the backcross of "Ganxiangzhan No. 1" carrying qECQ8 with the recurrent parent R838 (without qECQ8), we narrowed qECQ8 to a 187.5 kb interval between markers M33 and M37 on Chr8. Comparative transcriptomic analysis revealed that photosynthesis, glyoxylate and dicarboxylate metabolism, carbon fixation in photosynthetic organisms, and alpha-linolenic acid metabolism were induced in developing seeds of lines containing qECQ8. Furthermore, we identified two candidate genes in the qECQ8 region, including LOC_Os08g30550 (zinc knuckle family protein), a major candidate for genetic-assisted breeding of high-quality rice.

Conclusion: Our findings provide important genetic resources for targeted improvement of rice taste quality and may facilitate the genetic breeding of rice ECQ.

Background: Amorphophallus konjac (A. konjac), a perennial tuberous plant, is widely cultivated for its high konjac glucomannan (KGM) content, a heteropolysaccharide with diverse applications. The cellulose synthase-like (CSL) gene family is known to be a group of processive glycan synthases involved in the synthesis of cell-wall polysaccharides and plays an important role in the biological process of KGM. However, in A. konjac the classification, structure, and function of the AkCSLA superfamily have been studied very little.

Results: Bioinformatics methods were used to identify the 11 AkCSLA genes from the whole genome of Amorphophallus konjac and to systematically analyze their characteristics, phylogenetic evolution, promoter cis-elements, expression patterns, and subcellular locations. Phylogenetic analysis revealed that the AkCSLA gene family can be divided into three subfamilies (Groups I- III), which have close relationships with Arabidopsis. The promoters of most AkCSLA family members contain MBS elements and ABA response elements. Analysis of expression patterns in different tissues showed that most AkCSLAs are highly expressed in the corms. Notably, PEG6000 induced down-regulation of the expression of most AkCSLAs, including AkCSLA11. Subcellular localization results showed that AkCSLA11 was localized to the plasma membrane, Golgi apparatus and endoplasmic reticulum. Transgenic Arabidopsis experiments demonstrated that overexpression of AkCSLA11 reduced the plant's drought tolerance. This overexpression also inhibited the expression of drought response genes and altered the sugar components of the cell wall. These findings provide new insights into the response mechanisms of A. konjac to drought stress and may offer potential genetic resources for improving crop drought resistance.

Conclusion: In conclusion, the study reveals that the AkCSLA11 gene from A. konjac negatively impacts drought tolerance when overexpressed in Arabidopsis. This discovery provides valuable insights into the mechanisms of plant response to drought stress and may guide future research on crop improvement for enhanced resilience.

Background: Pseudomonas spp. have drawn considerable attention due to their rhizospheric abundance and exceptional plant growth-promoting attributes. However, more research is needed on the optimal application methods of Pseudomonas mosselii for rice growth, nutrient accumulation, and yield improvement. This research explored the application of the endophytic bacterium P. mosselii PR5 on rice cultivar BRRI dhan29 with four treatments: control, seedling priming, root drenching, and bacterial cell-free culture (CFC) foliar application.

Results: PR5 led to better rice growth, improved nutrient acquisition, and higher yields compared to the control, regardless of the application method used. The highest results in fresh weight of root (146.93 g/pot), shoot (758.98 g/pot), and flag leaf (7.88 g/pot), dry weight of root (42.16 g/pot), shoot (97.32 g/pot), and flag leaf (2.69 g/pot), and grains/panicle (224.67), were obtained from seedling priming treatment, whereas root drenching resulted in maximum plant height (105.67 cm), root length (49.0 cm), tillers/pot (23.7), and panicles/pot (17.67). In all three application methods, rice grain yield per pot was higher in PR5 inoculated treatments, compared to the control. The amount of P, Mg and Zn in the shoot and N, P, Ca, Mg and Si content in the flag leaf was significantly increased along with effective suppression of naturally occurring blast disease in bacterial CFC foliar application, validated by multivariate analysis.

Conclusion: Our results indicated that rice seedlings priming with PR5 improved rice growth, yield and nutrient uptake, whereas CFC foliar application significantly increased the concentration of most nutrients in the rice plant and suppressed the naturally occurring rice blast disease. This research highlights the significant potential of P. mosselii PR5 in enhancing rice growth, yield, and nutrient uptake, particularly through seedling priming and CFC foliar application methods.

Background: Rapeseed (Brassica napus L.) is an important oil and industrial crop worldwide. Black rot caused by the bacterial pathogen Xanthomonas campestris pv. campestris (Xcc) is an infectious vascular disease that leads to considerable yield losses in rapeseed. Resistance improvement through genetic breeding is an effective and sustainable approach to control black rot disease in B. napus. However, the molecular mechanisms underlying Brassica-Xcc interactions are not yet fully understood, especially regarding the impact of post-transcriptional gene regulation via alternative splicing (AS).

Results: In this study, we compared the AS landscapes of a susceptible parental line and two mutagenized B. napus lines with contrasting levels of black rot resistance. Different types of AS events were identified in these B. napus lines at three time points upon Xcc infection, among which intron retention was the most common AS type. A total of 1,932 genes was found to show differential AS patterns between different B. napus lines. Multiple defense-related differential alternative splicing (DAS) hub candidates were pinpointed through an isoform-based co-expression network analysis, including genes involved in pathogen recognition, defense signalling, transcriptional regulation, and oxidation reduction.

Conclusion: This study provides new insights into the potential effects of post-transcriptional regulation on immune responses in B. napus towards Xcc attack. These findings could be beneficial for the genetic improvement of B. napus to achieve durable black rot resistance in the future.

Hemp (Cannabis sativa L.) is an annual, and dioecious herb belonging to the Cannabaceae family. This plant is native to Central and Southeast Asia. The wild races of this species are commonly growing in Khyber Pakhtunkhwa and Punjab provinces, as well as in Islamabad, Pakistan. This study provides crucial insights into how environmental variables influence the wild hemp populations, which can be utilized in for conservation and breeding. The present study was aimed at evaluating the effects of key environmental factors such as altitude, geographical location, precipitation, relative humidity, maximum, minimum, and average temperature on 16 morpho-agronomic traits of a wild population of hemp growing in the Potohar Plateau and Lesser Himalayas. Our findings indicated that high relative humidity (> 64%), low average temperature (< 15 °C), intermediate average temperature (19-22 °C), and high average temperature (> 22 °C) played significant roles in determining the distribution pattern of the wild hemp. Correlation analysis demonstrated that average annual temperature contributed a higher percentage of variation in phenotypic diversity than geographic variables. Additionally, cluster analysis indicated three groups for the selected 35 populations. Clustering and Principal Component Analysis (PCA) of the morpho-agronomic traits indicated that group 1 from the Lesser Himalayas showed high relative humidity (> 64%) and low average temperature (< 15 °C). Conversely, Group 2 populations from the Potohar Plateau demonstrated intermediate average temperature (19-22 °C). There is an existence of Group 3 in the Potohar Plateau with a high average temperature (> 22 °C) compared to Group 1 and Group 2. Our examination highlights the complex interplay between ecological factors, and morphological attributes in native landraces of Cannabis sativa, giving significant insight into knowledge for preservation and breeding initiatives. A study of genetic diversity could complement morpho-agronomic traits in future research to learn more about how genetic variation affects environmental adaptation.

Background: Precision phenotyping of short-term transpiration response to environmental conditions and transpiration patterns throughout wheat development enables a better understanding of specific trait compositions that lead to improved transpiration efficiency. Transpiration and related traits were evaluated in a set of 79 winter wheat lines using the custom-built "DroughtSpotter XXL" facility. The 120 l plant growth containers implemented in this phenotyping platform enable gravimetric quantification of water use in real-time under semi-controlled, yet field-like conditions across the entire crop life cycle.

Results: The resulting high-resolution data enabled identification of significant developmental stage-specific variation for genotype rankings in transpiration efficiency. In addition, for all examined genotypes we identified the genotype-specific breakpoint in transpiration in response to increasing vapour pressure deficit, with breakpoints ranging between 2.75 and 4.1 kPa.

Conclusion: Continuous monitoring of transpiration efficiency and diurnal transpiration patterns enables identification of hidden, heritable genotypic variation for transpiration traits relevant for wheat under drought stress. Since the unique experimental setup mimics field-like growth conditions, the results of this study have good transferability to field conditions.

Background: This study clarified the synergistic relationship among annual changes to specify the changes in agro-meteorological factors, soil characteristics and peanut growth in saline-alkali land near the estuary of the Yellow River Delta. We aimed to find the key factors affecting peanut production to optimize and regulate peanut planting mode in saline alkali soil.

Results: The daily average temperature from early May to late September in Lijin and Kenli was above 24 °C, with 470-600 mm of precipitation. The sunshine duration was 7.9 h/day and 7.3 h/day and the accumulated temperature was 3742 °C and 3809 °C, in Lijin and Kenli, respectively. Agro-meteorological conditions were suitable for peanut growth and development with the consistent main developmental period in the two experiment regions. The best sowing period was when the soil temperature stabilized above 18 °C in early May, and the best harvest was in mid-September. The soil volumetric water content in Lijin concentrated among 25-40%. Salt was mainly distributed in the 40-60 cm soil layers, and increased rapidly to 2.5 g kg^- 1 in 0-20 cm cultivation layer in mid-May due to lack of precipitation. In Kenli experiment region, the soil volumetric water content ranged from 10 to 35%. Soil salinity was mainly distributed in the 20 cm soil layer, and the changes in salinity was little affected by precipitation. From mid-July to mid-August, the effective accumulated temperature of 5 cm soil layer was above 520 °C in both regions, which could ensure the normal pod development. The slow dynamic growth of kernel, high unfilled pod rate (26.99%) and low shelling rate (66.0%) might be the main reasons for low peanut yield in Lijin.

Conclusion: Soil salinity was the main factor affecting pod development and yield. It was also a key point in optimizing the peanut planting mode in the saline alkali land of the Yellow River Delta.