School of Plant and Environmental Sciences

Permanent URI for this community

https://hdl.handle.net/10919/91436
SPES was formed in 2017 from three departments: Crop and Soil Environmental Sciences; Horticulture; and Plant Pathology, Physiology, and Weed Science.

Browse

Browsing School of Plant and Environmental Sciences by Subject "0703 Crop and Pasture Production"

Now showing 1 - 9 of 9
  • Thumbnail Image
    Arabidopsis UMAMIT24 and 25 are amino acid exporters involved in seed loading
    Besnard, Julien; Zhao, Chengsong; Avice, Jean-Christophe; Vitha, Stanislav; Hyodo, Ayumi; Pilot, Guillaume; Okumoto, Sakiko (Oxford University Press, 2018-10-12)
    Phloem-derived amino acids are the major source of nitrogen supplied to developing seeds. Amino acid transfer from the maternal to the filial tissue requires at least one cellular export step from the maternal tissue prior to the import into the symplasmically isolated embryo. Some members of UMAMIT (usually multiple acids move in an out transporter) family (UMAMIT11, 14, 18, 28, and 29) have previously been implicated in this process. Here we show that additional members of the UMAMIT family, UMAMIT24 and UMAMIT25, also function in amino acid transfer in developing seeds. Using a recently published yeast-based assay allowing detection of amino acid secretion, we showed that UMAMIT24 and UMAMIT25 promote export of a broad range of amino acids in yeast. In plants, UMAMIT24 and UMAMIT25 are expressed in distinct tissues within developing seeds; UMAMIT24 is mainly expressed in the chalazal seed coat and localized on the tonoplast, whereas the plasma membrane-localized UMAMIT25 is expressed in endosperm cells. Seed amino acid contents of umamit24 and umamit25 knockout lines were both decreased during embryogenesis compared with the wild type, but recovered in the mature seeds without any deleterious effect on yield. The results suggest that UMAMIT24 and 25 play different roles in amino acid translocation from the maternal to filial tissue; UMAMIT24 could have a role in temporary storage of amino acids in the chalaza, while UMAMIT25 would mediate amino acid export from the endosperm, the last step before amino acids are taken up by the developing embryo.
  • Thumbnail Image
    Conidial production and viability of Calonectria pseudonaviculata on infected boxwood leaves as affected by temperature, wetness, and dryness periods
    Avenot, Herve F.; Baudoin, Antonius B.; Hong, Chuanxue (Wiley, 2021-10-31)
    Calonectria pseudonaviculata causes lesions on boxwood leaves and twigs. Controlled-environment experiments were conducted to determine the effects of temperature and leaf wetness period on C. pseudonaviculata sporulation on diseased (cv. Suffruticosa) leaves and of dryness periods and high temperature on conidial survival. Infected leaves were incubated in moist chambers and subjected to six temperatures (9, 13, 17, 21, 25, and 29°C) and six leaf wetness periods (0, 12, 24, 40, 48, and 72 h). Spore production was influenced significantly by wetness period, temperature, and their interaction. Increasing duration of leaf wetness and increasing temperature generally increased sporulation, with no sporulation occurring at 29°C or 9 and 13°C, except at 72 h of wetness exposure, while it was optimal at 21°C. Detached leaves with profuse conidia were subjected to a range of drying (relative humidity at 65%) times (0, 2, 4, 6, and 8 h) at two temperatures of 21 and 29°C. Conidia were then harvested and plated on water agar. Germinating conidia were counted to measure the spore viability. Spore mortality increased with increasing dryness duration at both temperatures but occurred more quickly and severely at 29 than 21°C. Overall, this study extended biological knowledge of conditions required for crucial stages of the C. pseudonaviculata disease cycle and the obtained results will be vital for developing boxwood blight forecasting and management tools.
  • Thumbnail Image
    Detailed characterization of the UMAMIT proteins provides insight into their evolution, amino acid transport properties, and role in the plant
    Zhao, Chengsong; Pratelli, Rejane; Yu, Shi; Shelley, Brett; Collakova, Eva; Pilot, Guillaume (Oxford University Press, 2021-09-30)
    Amino acid transporters play a critical role in distributing amino acids within the cell compartments and between plant organs. Despite this importance, relatively few amino acid transporter genes have been characterized and their role elucidated with certainty. Two main families of proteins encode amino acid transporters in plants: the amino acid-polyamine-organocation superfamily, containing mostly importers, and the UMAMIT (usually multiple acids move in and out transporter) family, apparently encoding exporters, totaling 63 and 44 genes in Arabidopsis, respectively. Knowledge of UMAMITs is scarce, based on six Arabidopsis genes and a handful of genes from other species. To gain insight into the role of the members of this family and provide data to be used for future characterization, we studied the evolution of the UMAMITs in plants, and determined the functional properties, the structure, and localization of the 47 Arabidopsis UMAMITs. Our analysis showed that the AtUMAMITs are essentially localized at the tonoplast or the plasma membrane, and that most of them are able to export amino acids from the cytosol, confirming a role in intra- and intercellular amino acid transport. As an example, this set of data was used to hypothesize the role of a few AtUMAMITs in the plant and the cell.
  • Thumbnail Image
    Mining germplasm panels and phenotypic datasets to identify loci for resistance to Phytophthora sojae in soybean
    Van, Kyujung; Rolling, William; Biyashev, Ruslan M.; Matthiesen, Rashelle L.; Abeysekara, Nilwala S.; Robertson, Alison E.; Veney, Deloris J.; Dorrance, Anne E.; McHale, Leah K.; Saghai-Maroof, Mohammad A. (Wiley, 2020-11-16)
    Phytophthora sojae causes Phytophthora root and stem rot of soybean and has been primarily managed through deployment of qualitative Resistance to P. sojae genes (Rps genes). The effectiveness of each individual or combination of Rps gene(s) depends on the diversity and pathotypes of the P. sojae populations present. Due to the complex nature of P. sojae populations, identification of more novel Rps genes is needed. In this study, phenotypic data from previous studies of 16 panels of plant introductions (PIs) were analyzed. Panels 1 and 2 consisted of 448 Glycine max and 520 G. soja, which had been evaluated for Rps gene response with a combination of P. sojae isolates. Panels 3 and 4 consisted of 429 and 460 G. max PIs, respectively, which had been evaluated using individual P. sojae isolates with complex virulence pathotypes. Finally, Panels 5–16 (376 G. max PIs) consisted of data deposited in the USDA Soybean Germplasm Collection from evaluations with 12 races of P. sojae. Using these panels, genome-wide association (GWA) analyses were carried out by combining phenotypic and SoySNP50K genotypic data. GWA models identified two, two, six, and seven novel Rps loci with Panels 1, 2, 3, and 4, respectively. A total of 58 novel Rps loci were identified using Panels 5–16. Genetic and phenotypic dissection of these loci may lead to the characterization of novel Rps genes that can be effectively deployed in new soybean cultivars against diverse P. sojae populations.
  • Thumbnail Image
    On the genetic architecture in a public tropical maize panel of the symbiosis between corn and plant growth-promoting bacteria aiming to improve plant resilience
    Yassue, Rafael M.; Carvalho, Humberto F.; Gevartosky, Raysa; Sabadin, Felipe; Souza, Pedro H.; Bonatelli, Maria L.; Azevedo, João L.; Quecine, Maria C.; Fritsche-Neto, Roberto (Springer, 2021-10-01)
    Exploring the symbiosis between plants and plant growth-promoting bacteria (PGPB) is a new challenge for sustainable agriculture. Even though many works have reported the beneficial effects of PGPB in increasing plant resilience for several stresses, its potential is not yet widely explored. One of the many reasons is the differential symbiosis performance depending on the host genotype. This opens doors to plant breeding programs to explore the genetic variability and develop new cultivars with higher responses to PGPB interaction and, therefore, have higher resilience to stress. Hence, we aimed to study the genetic architecture of the symbiosis between PGPB and tropical maize germplasm, using a public association panel and its impact on plant resilience. Our findings reveal that the synthetic PGPB population can modulate and impact root architecture traits and improve resilience to nitrogen stress, and 37 regions were significant for controlling the symbiosis between PGPB and tropical maize. In addition, we found two overlapping SNPs in the GWAS analysis indicating strong candidates for further investigations. Furthermore, genomic prediction analysis with genomic relationship matrix computed using only significant SNPs obtained from GWAS analysis substantially increased the predictive ability for several traits endorsing the importance of these genomic regions for the response of PGPB. Finally, the public tropical panel reveals a significant genetic variability to the symbiosis with the PGPB and can be a source of alleles to improve plant resilience.
  • Thumbnail Image
    Production, composition, and ecological function of sweet basil seed mucilage during hydration
    Zhou, Dongfang; Barney, Jacob; Welbaum, Gregory E. (Cambridge University Press, 2019-11)
    Sweet basil (Ocimum basilicum L.) fruit/pericarp produces mucilage that engulfs fruit and seed within minutes of hydration. Seed mucilage is produced by plant species adapted to arid, sandy soils, though its significance in determining ecological fitness is unclear. Basil fruit/seeds were examined using light and environmental scanning electron microscopy. Basil mucilage forms columnar structures that unfold from the pericarp upon hydration. Dilute hydrochloric acid removed mucilage and decreased water content 4-fold but did not inhibit laboratory seed germination. Fourier transform mid-infrared (FTIR) spectroscopy analysis showed mucilage is composed of hemicellulose that enabled basil seeds to cling to a smooth incline board set to a 70° steeper slope than seeds without mucilage. The fully hydrated seeds approached zero water potential, so the mucilage did not prevent full hydration. Seeds with mucilage had from 12 to 28% higher germination than seeds without mucilage planted in growing media. Seeds with mucilage also had higher survival percentages after 10 days. Basil fruit/seed mucilage provides a reservoir of loosely bound water at high water potential for seed germination and early seedling development, thus improving survivability under adverse moisture conditions.
  • Thumbnail Image
    Proof of Concept for Shoot Blight and Fire Blight Canker Management with Postinfection Spray Applications of Prohexadione-Calcium and Acibenzolar-S-Methyl in Apple
    Aćimović, Srđan G.; Meredith, Christopher L.; Santander, Ricardo Delgado; Khodadadi, Fatemeh (Scientific Societies, 2021-12-03)
    To reduce the severity of shoot blight and prevent the resulting development of cankers on perennial apple wood, we evaluated eight fire blight postinfection spray programs of prohexadione-calcium (PCA) alone or with acibenzolar-S-methyl (ASM) over 2 years. On mature trees of cultivar Royal Court, a single application of the high PCA rate (247 mg/liter) at 2 to 3 days after inoculation resulted in 89.5 and 69.5% reduction of shoot blight severity after inoculation. Two applications of PCA 247 mg/liter 12 or 14 days apart, with the first one applied 2 to 3 days after inoculation, resulted in 78.8 and 74.5% reduction of shoot blight severity in both years. A 100% control of canker incidence on perennial wood from infected shoots in both years was achieved with a single application of PCA (247 mg/liter) applied at 2 or 3 days after the inoculation, and three applications of PCA (125 mg/liter) + ASM (25 mg/liter) 12 to 16 days apart reduced canker incidence by 83.5 and 69% in the 2 years. The other programs with lower PCA rates and frequencies of application reduced shoot blight severity 50.8 and 51.8% (PCA) and 62.6 to 72% and 59.3% (PCA + ASM) over 2 years, respectively. Reduction of canker incidence on wood by the other programs was 66.5% and 69 to 90.4% in the two years, respectively. As fire blight cankers lead to death of dwarf apple trees and serve as primary sources of inoculum, our effective PCA and PCA + ASM programs could serve as viable postinfection management options. These treatments can reduce or prevent canker development and thus significantly abate tree losses in high-density apple orchards after fire blight epidemics occur.
  • Thumbnail Image
    Protoplast isolation, transient transformation, and flow-cytometric analysis of reporter-gene activation in Cannabis sativa L.
    Beard, Keely Marie; Boling, Audrey W. H.; Bargmann, Bastiaan O. R. (Elsevier, 2021-06-01)
    Cannabis sativa L. is a valuable, up-and-coming industrial crop with a substantially growing market. However, due to an extended period of legal restriction, research with cannabis has been limited, particularly in laboratory settings. Expanding the application of biotechnological techniques to cannabis can facilitate addressing species-specific impediments to improving crop traits and further fundamental understanding of its intricacies. Here, we describe application of protoplast transformation for the study of transient gene expression in a low-THC cannabis cultivar. To produce explant tissue as a source of protoplasts, a method for hormone-free in vitro micropropagation is established. Protoplasts are isolated from young leaves of the micropropagated stocks and transiently transformed with plasmid DNA carrying a fluorescent marker gene. This is the first report of protoplast transformation in this species. A protoplast isolation yield is achieved of up to 2 × 10 cells per gram of leaf material, vitality staining shows that up to 82 % of isolated protoplasts are viable, and quantification of the cells expressing a fluorescent protein indicates that up to 31 % of the cells can be successfully transformed. Additionally, protoplasts are transformed with an auxin-responsive reporter gene and the reaction to treatment with indole-3-acetic acid is quantified using flow cytometry. This work demonstrates that relatively minor modification of standard techniques can be used to study this important emerging crop. 6
  • Thumbnail Image
    Strain-level identification of bacterial tomato pathogens directly from metagenomic sequences
    Mechan Llontop, Marco Enrique; Sharma, Parul; Aguilera Flores, Marcela; Yang, Shu; Pollock, Jill; Tian, Long; Huang, Chengjie; Rideout, Steven L.; Heath, Lenwood S.; Li, Song; Vinatzer, Boris A. (Scientific Societies, 2019-12-12)
    Routine strain-level identification of plant pathogens directly from symptomatic tissue could significantly improve plant disease control and prevention. Here we tested the Oxford Nanopore Technologies (ONT) MinIONTM sequencer for metagenomic sequencing of tomato plants either artificially inoculated with a known strain of the bacterial speck pathogen Pseudomonas syringae pv. tomato (Pto), or collected in the field and showing bacterial spot symptoms caused by either one of four Xanthomonas species. After species-level identification using ONT's WIMP software and the third party tools Sourmash and MetaMaps, we used Sourmash and MetaMaps with a custom database of representative genomes of bacterial tomato pathogens to attempt strain-level identification. In parallel, each metagenome was assembled and the longest contigs were used as query with the genome-based microbial identification Web service LINbase. Both the read-based and assembly-based approaches correctly identified Pto strain T1 in the artificially inoculated samples. The pathogen strain in most field samples was identified as a member of Xanthomonas perforans group 2. This result was confirmed by whole genome sequencing of colonies isolated from one of the samples. Although in our case, metagenome-based pathogen identification at the strain-level was achieved, caution still needs to be exerted when interpreting strain-level results because of the challenges inherent to assigning reads to specific strains and the error rate of nanopore sequencing.