Plant Cultivars Research Articles

Acetylation participation in theanine biosynthesis: Insights from transcriptomics, proteomics, and acetylomics

Acetylation, a crucial post-translational modification, regulates transcriptional activation, enzymatic activity, and protein interactions, playing vital roles in plant physiology and metabolism. However, the regulatory mechanism of acetylation in the biosynthesis of theanine remains unexplored. This study aims to elucidate the regulatory role of acetylation on the biosynthesis of theanine using transcriptomics, proteomics, and acetylomics in tea leaves from three tea plant cultivars with markedly different theanine content. Nineteen theanine biosynthesis-related genes were identified in the transcriptome, with ten showing significant correlation with theanine content. Proteomic analysis revealed elevated expression levels of proteins associated with the biosynthesis of theanine precursor glutamate in leaves with high theanine content, such as GOGAT and GDH. Unexpectedly, the expression level of TS was inversely correlated with the theanine content in leaves. Several highly expressed acetylated proteins and sites, such as TS, GS, and GOGAT, were found in the acetylome of leaves with high theanine content. Acetylation at lysine 304 (K304) of the TS protein may significantly contribute to the abundant accumulation of theanine in leaves. Our findings indicate that acetylation modification may play a pivotal role in theanine biosynthesis, thereby offering novel insights into the development of high-theanine tea plant germplasm resources.

Productivity and quality parameters of Allium fistulosum L.

ABSTRACT The growing demand for non-traditional plant products encourages research into new plant species and cultivars. Allium fistulosum is the earliest leafy plant cultivated in the open field in Lithuania. Therefore, it is important to study plant cultivars and determine the harvesting time to obtain quality products. The study was conducted in the experimental vegetable field of the Institute of Horticulture of the Lithuanian Research Centre for Agriculture and Forestry in 2022–2023. The phenological stages of two different cultivars, morphological characteristics, productivity, and the plant's winter hardiness were observed. Measurements were performed and harvest was done three times: in spring, summer, and autumn. The results showed that genetic origin and harvesting time influenced differences in the morphometric parameters, productivity, and ascorbic acid accumulation of A. fistulosum cultivars. Cultivar ‘Bajkal’ is distinguished with longer and wider foliage, the highest productivity rate, and better adaptivity. This cultivar's most intensive plant growth was determined in autumn, but the highest weight of the plant reaching 0.5 kg was determined in spring. Cultivar ‘Marozka’ is distinguished by the higher ability of ascorbic acid accumulation compared with the cultivar ‘Bajkal’. The content of ascorbic acids reached 34.9 mg g−1 of cultivar ‘Marozka’ during the spring harvesting and up to 8,8 mg g−1 of ‘Bajkal’, respectively. The total sugar amount and weight of dry matter were more intensive in spring for both cultivars. In the cultivars ‘Marozka’ and ‘Bajkal’ leaves were found a higher amount of nitrates at 45.7 and 50.9 mg kg −1 in autumn.

The Effects of Planting Density, Training System and Cultivar on Vegetative Growth and Fruit Production in Young Mango (Mangifera indica L.) Trees

Increasing the planting density of mango orchards appears promising for obtaining higher yields, particularly during the first productive years. However, the challenge is to maintain a good balance between vegetative growth and fruit production in the longer term. The objective of this study was to decipher the effects of planting density, training system and cultivar on young mango trees’ growth and production. The experiment, conducted in North Queensland, consisted of five combinations of planting density and training system applied to the cultivars Keitt, Calypso and NMBP-1243. The planting densities were low (208 tree ha−1), medium (416 tree ha−1) and high (1250 tree ha−1). The closed vase conventional training system was applied at each density. Single leader and espalier on trellis training systems were applied at medium and high densities, respectively. The tree canopy dimensions were measured every 6 months from planting, and tree production was recorded from the third to the fifth years after planting. Vegetative growth and fruit production were the results of complex interactions between planting density, training system, cultivar and/or time. The expected increase in orchard yield with higher planting density was observed from the first productive year, despite lower individual tree production at high planting density. Lower vegetative growth and fruit production at high planting density were probably caused by competition between trees. NMBP-1243 and Keitt showed more rapid vegetative growth. Keitt was the most productive cultivar during the first three productive years. The detailed results of this study provide avenues to further explore the behaviour of mango trees at high planting densities.

Rhizobacterial diversity of Portuguese olive cultivars in the Douro valley and their potential as plant growth promoters.

This study investigated the bacterial communities in the rhizosphere of two traditional Portuguese olive cultivars, Cobrançosa and Negrinha de Freixo, in relation to soil properties. Additionally, we aimed to isolate and identify bacteria with potential for biocontrol and other plant growth-promoting traits from these rhizosphere communities. Bacterial communities in the olive rhizosphere were investigated using a metabarcoding approach and the soil physicochemical properties of the olive groves were also analyzed. Higher bacterial richness was associated with Negrinha de Freixo growing in soil with high organic matter content and water-holding capacity. In contrast, the soils of the Cobrançosa grove presented higher pH and electric conductivity. Negrinha de Freixo rhizosphere was enriched with ASVs (Amplicon Sequence Variants) belonging to Bacillus, Gaiella, Acidothermus, Bradyrhizobium, and uncultured Xanthobacteraceae. On the other hand, the Cobrançosa rhizosphere was characterized by higher relative abundance of Streptomyces and Sphingomonas. Bacterial isolation from the rhizosphere and screening for plant growth-promoting activities were also performed. Six bacteria strains, predominantly Bacillus isolated from Negrinha de Freixo, demonstrated antagonistic activities against the olive fungal pathogen Colletotrichum gloeosporoides and other plant growth promotion (PGP) traits. Our findings demonstrate that the structure of rhizosphere bacterial communities associated with olive trees is shaped by both plant cultivar and soil-related factors. The higher number of bacterial species in the rhizosphere of Negrinha de Freixo was related to a higher organic matter content and a greater abundance of isolates with plant growth promotion traits, particularly Bacillus strains.

New cultivars

Three new carnivorous plant cultivars are named and described: Cephalotus follicularis 'Thumbelina', Drosera 'Red Starburst', and Nepenthes 'Chonk'

Identifying the key meteorological factors to marketable tuber rate of potato: A 5-year field experiment in North China

ContextPotato is one of the staple food crops in China. Optimized agronomic management could enhance potato yield, while the economic benefits of farmers depend on both the yield and marketable tuber rate (MTR) of potato. The key meteorological factors to the variation of MTR of potato and the relationship between potato yield and MTR remain unclear. ObjectiveThe study aims to explore the key meteorological factors to the variation of MTR of potato and the relationship between potato yield and MTR. MethodsA 5-year (20172021) rainfed field experiment with 3-planting date and 3-cultivar maturity of potato was conducted to investigate the optimum combination of planting date and cultivar maturity for both high yield and MTR under different year types and the relationship between potato yield and MTR. The meteorological factors during three growth stages including planting to 10 d before the tuberization, the tuber formation period (10 d before the tuberization to 10 d after the tuber bulking), 10 d after the tuber bulking to maturity were used to identify the key meteorological factors to yield and MTR of potato. ResultsThroughout the experimental period, there were large variations in the fresh tuber yield and MTR of potato ranging between 4.827 t ha−1 and 061 %, respectively. Early- to middle planting of middle maturing cultivars under warm-wet years resulted in higher MTR, yield, and economic benefit compared to other combinations. Under warm-dry years, while early planting of early- to middle-maturing cultivars could achieve higher yield and MTR, farmers still suffer economic losses under most combinations of planting date and cultivar maturity. On the whole, there was a synergistical enhancement between yield and MTR of potato (R2=0.86, P<0.01). The precipitation and growing degree day (GDD) during tuber formation period (TF), precipitation before TF, and the interaction of precipitation and mean air temperature after TF could account for 77 % of the variations in total tuber yield while marketable tuber rate could be determined by the precipitation from planting to 10 d after the tuber bulking, the HDD during TF, and the interaction of precipitation and mean air temperature before TF (R2=0.79). Conclusions:Total tuber yield and MTR of potato could be synergistically enhanced by optimizing planting date and cultivar maturity. Compared with total tuber yield, MTR influences economic benefit of potato more significantly. Implications:These findings could serve as a valuable reference for determining the optimal planting date and cultivar maturity of potato under different hydrothermal year types to enhance the MTR, yield, and economic benefit of rainfed potato planting and provide an important implication on potato model improvement.

Effects of planting date and density on cotton cultivars in sub‐Saharan Africa rainfed conditions: A case study in Mali

AbstractMali is among Africa's three biggest cotton (Gossypium hirsutum L.)‐producing countries, and cotton growing is the principal driving force behind Mali's agricultural sector. Cotton production is rainfed on small‐scale family farms as a commercial crop alongside staple crops grown for subsistence. Cultivar choice, planting date, and planting density are critical elements for seed cotton yield that should be optimized. This study aimed to understand the interactions between planting dates and planting densities for the optimal production of four cotton cultivars in Mali. Two trials were set up in two seasons at the Finkolo and N'Tarla research stations. A split‐plot design with four replications was used, with planting dates (early and delayed by 3 weeks) as the main plots and planting density (41,666; 83,333; and 166,666 plants/ha) and cultivar (Malian NTA MS334, Togolese STAM 129A, Australian SIOKRA L23, and Brazilian BRS 293) as the subplots. In 2021, seed cotton yield was 1263 kg/ha for early planting versus 361 kg/ha for late planting. Medium and high planting densities produced the same yield level, higher than the low planting density. Regardless of the planting density, early plantings' average capsular weight and seed index were higher than those of late plantings. The African cultivars (STAM 129A and Malian cultivar NTA MS334) were the most productive. Due to significant interactions on fiber percentage and to optimize cotton yields in Mali, planting should be early, with planting densities higher than 41,666 plants/ha, and either of the African cultivars tested should be used.

Effect of symbiotic microbiota and arginine on host plant selection by the tea green leafhopper in tea cultivation

The tea green leafhopper (TGLH), Empoasca (Matsumurasca) onukii Matsuda, poses a significant challenge to tea cultivation in East Asia because of its ability to infest specific tea plant cultivars. Here, we investigated the complex interactions between TGLHs, various tea cultivars, and their symbiotic microbiota, especially the effect of arginine on host selection. A detailed two-year field study involving 16 tea cultivars, coupled with controlled laboratory and field experiments, was conducted to establish a clear link between TGLH infestation and the arginine content of tea plants. Metagenomic analysis revealed a predominance of bacterial taxa in TGLHs, primarily from the phylum Proteobacteria, with significant contributions from orders such as Pseudomonadales, Enterobacterales, and Flavobacteriales, which are crucial for the biosynthesis of essential amino acids but lack the argF gene necessary for arginine synthesis. The absence of the argF gene indicates the potential presence of microbial-mediated dietary adaptation strategies in TGLHs. Additionally, our research examines microbial diversity within TGLH populations and confirms the critical role that symbiotic bacteria play in influencing dietary preferences. The results of our study provide insights into the dynamic interplay between pests, plants, and microorganisms. Our findings are preliminary, and further research is needed to explore the potential applications of symbiotic bacteria in sustainable tea cultivation and integrated pest management strategies.

Customized Plant Growth Promotion with Soil- and Cultivar-Compatible Microbial Biofertilizers

Organic fertilizers and microbial biofertilizers are now widely recognized to effectively complement traditional mineral fertilizers for plant growth. The present study shows that bio-organic fertilizers can be enhanced by the addition of functional plant-growth-promoting rhizobacteria (PGPR) that provide additional benefits to plants. We hypothesized that not all beneficial soil bacteria are functional in different farm soils and plant varieties; hence, the most effective PGPR that are suitable to each farm’s individual cropping conditions were selected. Five different field soils and their respective crops were tested for compatibility with six microbial biofertilizers (including three new bacterial strains) to supplement a commercially available bio-organic fertilizer. In pot trials with lucerne plants, four out of the six microbial treatments led to significant (p &lt; 0.05) growth promotion benefits (up to 79.8% more leaves and dry weight) compared to mock-treated or bio-organic fertilizer-only-treated control plants. A trial with industrial hemp demonstrated that compatibility with PGPR occurs in a cultivar-specific manner, leading to growth promotion ranging from −3.4% to 68.9%, with each cultivar displaying a preference for a different PGPR. Finally, pot trials with Rhodes grass and two different soils demonstrated high yield increases compared to control plants, with Bacillus amyloliquefaciens 33YE being most effective for one soil and Bacillus velezensis UQ9000N/Pseudomonas lini SMX2 for the other soil. Yield advantages reduced after several cuts of grass, but a repeat biofertilizer treatment at 69 days after the initial treatment restored high yield advantages, with the same PGPR again being most effective. These results demonstrate the importance of customization of microbial inoculants to identify the most compatible PGPR–cultivar–soil interaction. The customization of microbial biofertilizers to soils and plant cultivars, combined with complementary fertilizer applications, can potentially lead to more reliable and more sustainable agricultural practices.

Stem Rust Resistance and Resistance-Associated Genes in 64 Wheat Cultivars from Southern Huanghuai, China.

Wheat stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is a devastating fungal disease that affects wheat globally. The planting of resistant cultivars is the most cost-effective strategy for controlling this disease. The Huanghuai region, as a major wheat-growing area, plays a crucial role in the spread and prevalence of wheat stem rust in China. In this study, 64 wheat accessions from this region were tested at the adult stage against two major Pgt races, 34MKGQM and 21C3CTHQM. DNA markers associated with the known resistance genes Sr31, Sr24, Sr25, Sr26, and Sr38 were measured to determine their presence in the tested accessions. In the 2023 field tests, 5 (7.8%) accessions were immune to 21C3CTHQM and 34MKGQM, while 35 (54.7%) and 39 (60.9%) were moderately resistant and resistant, respectively. The remaining 20 (30.7%) accessions were moderately susceptible and susceptible. In the 2024 tests, 12 (18.8%) and 14 (21.9%) entries were immune to both races; 29 (45.3%) and 30 (46.9%) were moderately resistant and resistant, respectively. Only two cultivars, Xinong 816 and Yimai 211, were immune in both years, and three entries showed some degrees of resistance in both years. Seven cultivars, including Zhongzhimai 23, Longxing 1, Yunong 937, Huaguan 301, Wanke 800, Shaanhe 285, and Yunong 612, showed increased susceptibility. DNA markers showed that 30 entries carried Sr31, while 6 entries carried Sr38. Genes Sr24, Sr25, and Sr26, which confer good resistance to the globally prevalent cultivars TKTTF and TTTRF, were absent from the set of tested entries. While this study surveyed the resistance levels of a cross-section of wheat from the southern part of the Huanghuai region and confirmed the presence of two known resistance genes, the basis of immunity or high levels of resistance in several lines remains obscure.

Molecular Identification Validates Morphological Identification of Javanese Cardamom from Banyumas in Central Java, Indonesia

Cardamom is one of the prominent plants with significant economic value in the Banyumas Regency, Central Java, Indonesia. Although Javanese cardamom is traditionally categorized under Amomum compactum, the morphological variations observed create ambiguity about its exact species status. DNA barcoding using the maturase K (matK) and ribulose-bisphosphate carboxylase (rbcL) genes is proven as a reliable technique to elucidate the taxonomic status of morphological variable plant cultivars. This study aimed to characterize cardamom from Banyumas Regency using morphological and molecular approaches for taxonomic status identification and genetic diversity evaluation. The matK and rbcL genes were selected as genetic markers and sequenced using a bidirectional sequencing technique. Morphological examination showed significant color variations at the cardamom stem base. All samples had high genetic identities to reference species in databases and were supported by high query cover and zero e-values. Therefore, molecular characterization, alongside geographic distribution assessment, established that this plant belongs to a single species, Amomum compactum. Additionally, the analysis conducted showed a low level of genetic diversity, as evidenced by haplotype and nucleotide diversity. Low-level genetic diversity provides additional data to convince that cardamon in Banyumas Regency belongs to a single species. These results are essential data in seed selection for further cultivation.

Crossing a CRISPR/Cas9 transgenic tomato plant with a wild-type plant yields diverse mutations in the F1 progeny.

Generating CRISPR/Cas9-mediated mutants in tomato (Solanum lycopersicum L.) involves screening shoots regenerated from cultured cells transformed with a T-DNA harboring sequences encoding Cas9 and single guide RNAs (sgRNAs). Production of transformants can be inconsistent and obtaining transformants in large numbers may be difficult, resulting in a limited variety of mutations. Here, I report a method for generating various types of mutations from one transgenic plant harboring the CRISPR/Cas9 system. In this method, a wild-type plant was crossed with a T0 biallelic mutant expressing two sgRNAs targeting the RIPENING INHIBITOR (RIN) gene, and the resulting F1 seedlings were classified using a kanamycin resistance marker on the T-DNA. Genotyping of the RIN locus revealed that kanamycin-sensitive F1 seedlings, which carried no T-DNA, always harbored the wild-type allele and a mutant allele from the transgenic parent. Kanamycin-resistant F1 seedlings, which do carry the T-DNA, harbored a variety of novel mutant alleles, but not the wild-type allele, suggesting that it was mutated during crossing. The novel mutations included one-base insertions or short deletions at each target site, or large deletions across the two target sites. This method was also successfully applied to produce mutations in Geranylgeranyl pyrophosphate synthase 2 (GGPS2). Because this method involves crossing rather than transformation, it can be readily scaled up to produce numerous novel mutations, even in plant species or cultivars for which transformation is inefficient. Therefore, when initial transgene experiments fail to induce the desired mutation, this method provides additional opportunities for generating mutants.

Root morphology parameters and nutrient acquisition capabilities of grafted tomato plants in root-restricted conditions are subject to salinity and rootstock characteristics

ABSTRACT A tomato cultivar ('Izmir F1') grafted onto six commercially available rootstocks ('Arnold', 'Dohkko', 'Emperador', 'He-man', 'Kaiser', and 'Suzuka') together with self-grafted plants of the tomato cultivar (Izmir/Izmir) were included in a pot experiment. Growth, root morphology and nutrient uptake parameters were evaluated under different salinity conditions (0 and 50 mM NaCl). Grafting increases root length, specific root length, and root length ratio, which enhances the capabilities of hetero-grafted plants to exploit a larger volume of soil or otherwise increase root density under root restriction conditions. Since the root traits and nutrient concentrations in hetero-grafted variants were less impacted by a change in the salinity level, the use of specific rootstocks (‘Arnold,’ ‘Dohkko,’ ‘Kaiser’) could contribute to a steadier growth and yield of tomato plants under fluctuating salinity levels in the irrigation water. The hetero-grafted tomato plants (Dohkko/Izmir, Suzuka/Izmir) demonstrated higher Na sequestration/compartmentalization capabilities than the self-grafted (Izmir/Izmir) plants which helps to maintain a more appropriate K+/Na+ ratio. By exhibiting lower translocation indexes of some heavy metals (Al, Ni, Zn, and Cd), appropriate rootstock/scion combinations might be a useful tool for reducing the risk of their accumulation in edible plant organs.

Growth and Fecundity of Nonnative Blue Honeysuckle Cultivars: Comparisons with Native and Invasive Congeners in a Maine Field Trial

Blue honeysuckle (Lonicera caerulea) is a circumpolar species complex with representatives in Europe, Asia, and North America. Although honeysuckles (Lonicera spp.) from Eurasia have a history of invasiveness in North America, farmers and homeowners are interested in growing nonnative blue honeysuckle hybrids because of their edible blue fruits. To assess whether these cultivars and closely related native blue honeysuckles (Lonicera caerulea subsp. villosa) might have similar growth and fecundity, we planted five nonnative cultivars of blue honeysuckle and five native genotypes in a common garden in Orono, ME, USA, along with invasive red-fruited honeysuckles [Tatarian honeysuckle (Lonicera tatarica) and European fly honeysuckle (Lonicera xylosteum)] for comparison. Rooted cuttings were planted into a field plot in Jun 2016 and fully maintained during the first season; thereafter, maintenance consisted of weeding once annually. Seventy-three percent of native blue honeysuckle plants survived to the end of the study, whereas survival and growth of nonnative cultivars were more robust. In 2021, nonnative cultivars had an average height of 81 cm and width of 86 cm, which were 2.8 times the height and 2.9 times the width of surviving native plants. The estimated canopy volumes of nonnative blue honeysuckles were an average of 20 times those of their native counterparts. The bloom periods of native and nonnative blue honeysuckles overlapped considerably. However, only seven of the 22 living native plants produced fruits in 2021, with an average of three fruits per plant among them. In contrast, nearly all plants of the nonnative cultivars produced fruits, with an average of 616 fruits per plant. In comparison, the red-fruited invasives had an average of 9739 fruits per plant. Native blue honeysuckles produced very few seeds, whereas nonnative cultivars had an average of 13,918 seeds per plant, which was approximately one-fourth the number produced by invasive red-fruited honeysuckles. We concluded that native and nonnative genotypes of blue honeysuckle differ strikingly in survival, growth, and production of fruits and seeds. However, invasive red-fruited honeysuckles grew faster with higher fecundity than nonnative blue honeysuckles in our full-sun landscape. Because bloom times overlapped substantially between native and nonnative blue honeysuckles, the potential for gene flow to occur from planted cultivars into native populations merits consideration. Several possible explanations of differences in performance among blue honeysuckles include hybrid vigor of cultivars or shallow rooting or poor adaptability of native genotypes to the environment of the common-garden trial. Our results, which demonstrated that nonnative blue honeysuckles are likely to be distinct from their native relatives in terms of competitiveness and fecundity, suggest that caution is warranted during the introduction and cultivation of agricultural genotypes.

Characteristic of phenotype, amino acids and volatile compounds for fresh tea leaves of Korean tea cultivars (Camellia sinensis (L.) O. Kuntze)

Tea (Camellia sinensis (L.) O. Kuntze) is a popular beverage consumed worldwide. To establish fundamental scientific data, we analyzed the amino acids and volatile compounds in seven tea cultivars grown in Korea investigated phenotype also. Phenotypically, the leaf area and greenness index of young shoots and leaf blades were particularly different among the four Korean cultivars. Nine amino acids were detected from each cultivar, with the total amino acid and theanine contents being 9.08–41.42 and 2.81–24.60 mg/g, respectively. Moreover, 107 volatile compounds were identified as common components among tea cultivars using headspace solid-phase microextraction / gas chromatography–mass spectrometry (HS-SPME/GC-MS), and 38 key compounds were identified using partial least squares-discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA). The (Z)-linalool oxide (furanoid) concentrations were significantly high in Korean tea plant cultivars, and linalool concentrations were also high or low, but had high relative contents. Linalool and its various oxides are the major compounds responsible for the tea aroma. In conclusion, Korean tea cultivars have distinct characteristics, and the results of this study will form the basis for identifying Korean tea plant cultivars that can produce high-value tea products.

Sweet Pepper Farming Strategies in Response to Climate Change: Enhancing Yield and Shelf Life through Planting Time and Cultivar Selection

Climate change is an important concern worldwide. This huge change is causing a negative impact on crop productivity throughout the whole world and shows some drastic effects on sensitive crops including sweet pepper and other kinds of chilies. These stresses have a negative effect on vegetable growth, fruit quality, and fruit yield. Besides these stresses, accurate planting time is the utmost factor in increasing the crop potential and its productivity. Therefore, this study aimed to evaluate the optimal planting date and best-performing cultivar for sweet pepper to maximize crop productivity, growth, yield, and fruit shelf life under the impacts of climate change. The experiment was conducted in Multan, Pakistan (30° 25 N and 71° 30 E). In this experiment, four planting dates (10 January, 25 January, 10 February, and 25 February) with three cultivars (Ganga, Winner, and Savio) were grown with three replications (each year) during 2020 and 2021. Our findings showed that plant growth, fresh and dry biomass, yield, and yield attributes were statistically higher in earlier plantings, and lower in delayed planting. Regarding the cultivars in both years, ‘Winner’ performed better in all growth and yield parameters as compared to other growing cultivars. Lower weight loss and decay incidence were reported in ‘Winner’ cultivar. Additionally, ‘Winner’ cultivar showed a higher sensory score as compared to the other cultivar in both years. From the results, we conclude that the nursery of sweet pepper plants should be planted on the 25 January to attain higher crop productivity, and the cultivar ‘Winner’ showed promising effects so it should be planted for better yield.

Transcriptome Reveals the Regulation of Exogenous Auxin Inducing Rooting of Non-Rooting Callus of Tea Cuttings.

Cuttage is the main propagation method of tea plant cultivars in China. However, some tea softwood cuttings just form an expanded and loose callus at the base, without adventitious root (AR) formation during the propagation period. Meanwhile, exogenous auxin could promote the AR formation of tea plant cuttings, but the regulation mechanism has not yet explained clearly. We conducted this study to elucidate the regulatory mechanism of exogenous auxin-induced adventitious root (AR) formation of such cuttings. The transcriptional expression profile of non-rooting tea calluses in response to exogenous IBA and NAA was analyzed using ONT RNA Seq technology. In total, 56,178 differentially expressed genes (DEGs) were detected, and most of genes were significantly differentially expressed after 12 h of exogenous auxin treatment. Among these DEGs, we further identified 80 DEGs involved in the auxin induction pathway and AR formation. Specifically, 14 auxin respective genes (ARFs, GH3s, and AUX/IAAs), 3 auxin transporters (AUX22), 19 auxin synthesis- and homeostasis-related genes (cytochrome P450 (CYP450) and calmodulin-like protein (CML) genes), and 44 transcription factors (LOB domain-containing protein (LBDs), SCARECROW-LIKE (SCL), zinc finger protein, WRKY, MYB, and NAC) were identified from these DEGs. Moreover, we found most of these DEGs were highly up-regulated at some stage before AR formation, suggesting that they may play a potential role in the AR formation of tea plant cuttings. In summary, this study will provide a theoretical foundation to deepen our understanding of the molecular mechanism of AR formation in tea cuttings induced by auxin during propagation time.

Cultivars and Production Environments Shape Shoot Endophyte Profiles of Boxwood with Different Blight Resistance

Phyllosphere colonizers, including bacteria and fungi, are critical for plant growth and health. However, how they are affected simultaneously by the host plant cultivar, local environment, and agricultural practices was not well understood. We used boxwood, an iconic landscape plant and a major evergreen shrub crop in the United States nursery industry, as a model plant and sequenced 16S rRNA and ITS amplicons to examine the assemblages of endophytic bacteria and fungi in the shoots of four cultivars representing three levels of boxwood blight resistance under two distinct climates and production systems in Oregon and Virginia. Cultivar and local environment were the two main drivers shaping the composition and structure of the boxwood endophytic microbial community, particularly the fungal community. Three bacterial and seven fungal genera were consistently identified with high prevalence and abundance as the core taxa from four cultivars and two locations across three sampling times. The microbial composition varied among the levels of boxwood blight resistance, and taxa specific to the tolerant cultivar were fewer compared to the susceptible one. Identification of these microbial indicators, along with the core taxa, is foundational for developing a microbiome-based plant breeding program and a systems approach to improve boxwood health and production under a changing climate. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Effects of Foliar Selenium Spraying on Yield and Quality Characteristics of Fenugreek (Trigonella foenum graecum L.) at Different Plant Growth Stages

ABSTRACT The study was conducted to determine the effects of foliar selenium spraying on the yield and quality characteristics of fenugreek in different plant growth stages. The experiment was established according to the split-split block experimental design. In the study, the main plots, sub-plots, and sub-sub plots consist of different plant growth stages (seedling, flowering, and seed formation periods), cultivars (Gürarslan, Çiftçi, and Berkem), and selenium doses (Control, 25, 50 and 75 g ha−1), respectively. Applying selenium at different plant growth stages was a statistically significant effect on the number of pods and protein content in the first year and on the number of branches in the second year. According to different plant growth stages, the highest results for the number of pods per plant, protein content and number of branches per plant were obtained during the flowering period. Applied selenium doses were ineffective on all investigated plant parameters except for plant height and number of seeds per pod in the first year. The highest results in the plant height and the number of seeds per pod were obtained from 75 g ha−1 selenium application and the control parcels, respectively. Biological yield and protein content were significant among cultivars only in the second year. The highest results in terms of biological yield and protein content were obtained in Gürarslan and Çiftçi cultivars. This study revealed that more studies are needed to determine the effects of selenium applications on medicinal and aromatic plants.

First Report of Xanthomonas euvesicatoria pv. sesami Causing Leaf Spot on Sesame (Sesamum indicum L.) in South Carolina, USA.

Sesame (Sesamum indicum L.) is an annual plant known as one of the first domesticated oilseed crops. It is cultivated worldwide, mostly in Asia, Africa, and the Americas (Singh, 2006). In August 2022 and September 2023, dark angular necrotic spots on leaves and stems (100% incidence), blights, and severe defoliation were observed in a 4-acre rainfed sesame field located in the Colleton County of South Carolina, USA (Fig. S1). Bacterial streaming from cut leaf lesions was observed from diseased plants in both years. Two plants were collected for pathogen isolation in 2023. Symptomatic leaves were surface sterilized with 70% ethanol for 1 min and dried in a laminar flow hood. For each isolate, four sterile toothpicks were used to poke lesion margins and stirred in 300 µl of sterile distilled water in a 2-ml sterile microcentrifuge tube and soaked at room temperature (c. 21 °C) for 10 min. Each bacterial suspension (10 µl) was streaked on nutrient agar (NA) in a Petri dish. Convex and mucoid yellow colonies formed after a 48-h incubation at 28°C in the dark. Two isolates (S813 and S814), one from each plant, were obtained by transferring single colonies to new NA plates. Both isolates were preliminarily identified as Xanthomonas [S813: X. campestris (P = 0.53); S814: X. campestris (P = 0.77)] using a Biolog Microbial Identification System (GEN III Microplate; Identification Database v.2.8.0.15G). PCR amplification of the atpD and dnaK genes was performed for both isolates using the conditions described in Félix-Gastélum et al. (2019). The sequences of both amplicons are 100% identical for each gene between the two isolates. PCR and sequencing of the gyrB gene was also done for S813 with the primers from Young et al. (2008). The atpD (S813/S814), dnaK (S813/S814), and gyrB (S813) sequences (GenBank accessions: PP507118 to PP507120) showed the best match with 100% identity to the corresponding gene sequences [GenBank accessions: KJ491167 (100% coverage), KJ491257 (99% coverage), EU285201 (100% coverage)] of the X. euvesicatoria pv. sesami (=X. campestris pv. sesami) type strain LMG865 (Constantin et al. 2015, Parkinson et al. 2009). A neighbor joining tree with the concatenated sequences of these three genes (2,210 nt) showed that S813 and LMG 865 had the closet relationship with X. euvesicatoria pv. alfalfae (CFBP3836, Fig. S2). To fulfill Koch's postulates, three healthy sesame plants (cultivar Shirogoma) were spray inoculated separately with each suspension of S813 and S814 in sterile tap water until runoff (approx. 5×108 CFU/ml). Two sesame plants were sprayed with sterile tap water and served as negative control. All plants were maintained in a greenhouse at approximately 28/20°C (day/night) with natural photoperiod. Dark leaf spots and leaf yellowing were observed on inoculated plants 7 to 14 days after inoculation. No disease symptom was observed on the control plants. Bacteria were reisolated from leaf spots of the inoculated plants and confirmed to be X. euvesicatoria pv. sesami based on atpD and dnaK sequences. The disease was first reported in Sudan (Sabet and Dowson, 1960), after which it was reported in USA (Isakeit et al., 2012) and Mexico (Félix-Gastélum et al. 2019). To the best of our knowledge, this is the first report of this disease in South Carolina, USA. Since the interest of sesame to the farmers is increasing in the southeastern USA, it is necessary to perform further research to examine the disease distribution and its economic impact.