Publications

4495

Comparison of the metabolic changes prior to symptom development upon infection with Candidatus Liberibacter asiaticus (CLas), the bacterium associated with citrus greening disease, between citrus hosts with different tolerances is lacking. The objective of this study was to compare the early response of Lisbon lemon (Citrus limon) and Washington navel orange (Citrus sinensis [L.] Osbeck), two citrus species commercially important to California, to CLas through graft inoculation. Here, we compare the transcriptome, proteome, and metabolome response, using RNA sequencing, liquid chromatography tandem mass spectrometry, and 1H nuclear magnetic resonance, respectively, from our two recently published studies examining the response of the lemon and navel oranges separately, and introduce new micronutrient data from inductively coupled plasma mass spectrometry analysis, focusing on lemons at 10 and 14 weeks postgrafting (wpg), and navels at 8 and 18 wpg, prior to symptom development. Several micronutrients accumulated in presymptomatic infected lemons compared with controls, whereas little change was observed in the navels. Photosynthesis proteins were substantially altered by CLas infection in navels, with fewer changes observed in lemons. The metabolome differed between control and infected navels throughout infection, although differences between control and infected lemons were identified only after symptom expression. Taken together, these findings highlight differences in response to CLas between two varieties with differing tolerances. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

‘Candidatus Liberibacter asiaticus,’ an uncultured α-proteobacterium, is associated with citrus huanglongbing (HLB, yellow shoot disease), a destructive disease threatening citrus production worldwide. Here, we reported the draft genome sequence of ‘Ca. L. asiaticus’ strain Myan16 from an HLB-affected lime tree in Myitkyina, Kachin State, Myanmar. The strain Myan16 genome is 1,229,102 bp with an average G+C content of 36.4%, along with a circular prophage: P-Myan16-2 (36,303 bp, type 2). This is the first genome sequence of a ‘Ca. L. asiaticus’ strain from Myanmar, which will enrich the current ‘Ca. L. asiaticus’ genome sequence database and facilitate HLB epidemiology research in Asia and world.

Abstract Me.tha.no.tri.cha'les. N.L. fem. n. Methanothrix type genus of the order; suff. ‐ ales the ending to denote an order; N.L. fem. pl. n. Methanotrichales the order of Methanothrix . Cells are nonmotile, sheathed rods with flat ends. Gram‐stain negative. Lipids contain myo ‐inositol, ethanolamine, and galactose as the polar head groups. Species are oxygen‐tolerant anaerobe. However, growth and methanogenesis can only occur in strictly anaerobic and highly reducing conditions. Energy is obtained by splitting acetate into methane and CO 2 . When cocultured with electrogenic Geobacter spp., CO 2 is reduced to methane via direct interspecies electron transfer (DIET). Optimum growth pH range is 7.0–7.8. Mesophilic and thermophilic. Optimum growth temperatures are 34–37°C for mesophilic strains and 55–60°C for thermophilic strains. They occupy a wide range of anoxic habitats including anaerobic river mud, paddy field soil, hot springs, thermal lakes, thermophilic, and mesophilic anaerobic wastewater digesters treating domestic wastes; granular sludge, anaerobic fixed‐bed reactors, and other types of anaerobic systems. Genome sequences have been determined for strains of all three of the described species in the order, and the genome size ranges from 1.9 to 3.0 Mb. The order Methanotrichales consists of one family Methanotrichaceae . Although all three described species are currently classified in a single genus Methanothrix , phylogenomic analyses suggest that two species should be transferred to novel genera. DNA G + C content (mol%) : 51–61 (Genome). Type genus : Methanothrix Huser et al. 1982, VL10. Taxonomic and Nomenclature Notes According to the List of Prokaryotic names with Standing in Nomenclature (LPSN), the taxonomic status of the order Methanotrichales is: synonym (and no standing) (last update, February 2025) * . Correct name: Methanosarcinales LPSN classification: Archaea / Methanobacteriati / Methanobacteriota / Methanosarcinia / Methanosarcinales The order Methanotrichales can also be recovered in the Genome Taxonomy Database (GTDB) as o__Methanotrichales (version v220) ** . GTDB classification: d__Archaea / p__Halobacteriota / c__Methanosarcinia / o__Methanotrichales * Meier‐Kolthoff et al. ( 2022 ). Nucleic Acids Res , 50 , D801 – D807 ; DOI: 10.1093/nar/gkab902 ** Parks et al. ( 2022 ). Nucleic Acids Res , 50 , D785 – D794 ; DOI: 10.1093/nar/gkab776

Abstract Aster yellows (AY) group phytoplasmas affect plants by causing a general reduction in quantity and quality of yield. The most severely affected hosts are carrot, lettuce, onion, spinach and several ornamental crops, including aster, gladiolus, hydrangea, chrysanthemum and purple coneflower. Disease incidence may vary from year to year depending on the population trend of the vectors in the field. Infection rates varying from 20 to 30% were observed in lettuce and ranunculus fields in southern Italy (Marcone et al., 1995; Parrella et al., 2008). In Oklahoma, USA, according to Errampalli et al. (1991), AY group phytoplasma infections occurred in 80% of lettuce plants and 28% of carrots. In Ohio, disease incidence of 100% has been recorded in lettuce fields (Zhang et al., 2004). A major outbreak of AY disease occurred in 2000 in Texas that affected several vegetable crops. Among them, carrot was most severely damaged with infection rates that ranged from to 50 to near 100% (Lee et al., 2003). A severe AY disease of chrysanthemum which induced losses of 70 to 80% of the crop has been reported from China (Min et al., 2008) whereas losses of 90% were recorded in AY-affected aubergines in Bangladesh (Kelly et al., 2009). Infection rates of 60 and 99% were recorded in Hungary for AY-affected sugarbeet plants and India for AY-affected Jatropha curcas plants, respectively (Mumford et al., 2000; Kumar et al., 2010b). However, there are also several reports on sporadic occurrence and generally low incidence of AY group phytoplasmas in vegetable and ornamental crops (Smith et al., 1988; Vibio et al., 1995; Bertaccini et al., 1998). Cassava witches' broom, a disease affecting cassava in South East Asia (Vietnam, Thailand, Cambodia, Laos, China and the Philippines) is caused by 16SrI phytoplasma. The disease has resulted in significant reductions in cassava root starch content and up to 80% yield loss in parts of Vietnam (Anon., 2014).