The complete genome sequence of a putative novel cytorhabdovirus identified in Chelidonium majus in China.

A new cytorhabdovirus, tentatively named "chelidonium yellow mottle associated virus" (CheYMaV), was identified in Chelidonium majus with yellow mottle symptoms by high-throughput sequencing and RT-PCR. Its genome is 12,121 nucleotides in length and contains eight open reading frames (ORFs) in the order 3'-N-P'-P-P3-M-G-P6-L-5'. Amino acid sequence comparisons between the putative proteins of CheYMaV and the corresponding proteins of other cytorhabdoviruses showed that it shares the highest sequence similarity with Trifolium pratense virus A (TpVA, MH982250) and Glehnia littoralis virus 1 (GllV1, BK014304), but with sequence identity values below the species demarcation threshold for cytorhabdoviruses (< 80%). Phylogenetic analysis showed that CheYMaV is most closely related to TpVA and GllV1. CheYMaV should therefore be considered a new member of the genus Cytorhabdovirus. This is the first report of a cytorhabdovirus identified in Chelidonium majus.

First report of cucumber green mottle mosaic virus infecting Cynanchum rostellatum in China.

Cucumber green mottle mosaic virus (CGMMV) was first discovered on cucumber in the United Kingdom in 1935 (Ainsworth, 1935), and has spread worldwide except to Antarctica (Jones, 2021). Given its extensive damage, it is considered an important pathogen on global cucurbit plants and fruit crops. In China, CGMMV was first reported on pumpkin in Guangxi Province in 2003 (Qin et al., 2005), and occurred on 34 plants species across 23 provinces (Liu et al., 2016). Cynanchum rostellatum is a member of the family Apocynaceae. In July 2021, leaves of C. rostellatum exhibiting virus-like symptoms (yellowing, severe crinkling, deformation) were observed and collected in Liaoning Province, China. Aphids were also observed on the leaves and stems (Fig. S1) of the plants and were collected. Total RNA was extracted from diseased leaves following the CTAB method, followed by the depletion of ribosomal RNAs (rRNA) with TIANSeq rRNA Depletion Kit (Tiangen, China). The RNAs were, then processed into a DNBSEQ LncRNA-Seq library, and sequenced on the MGISEQ-2000 platform at BGI Genomics (Wuhan, China). A total of 106.98 M clean reads were obtained after data filtering using SOAPnuke software (BGI, China). The clean reads were assembled into contigs using CLC Genomics Workbench 11 (Qiagen, USA) and Trinity v2.0.6 (Haas et al., 2013). A contig (4,760 reads, average coverage:73.76) of 6,391 nucleotides was found to share the highest sequence identity (99.83%) with CGMMV isolate GDLZ (MK933286), irrespective of other virus-like contigs related to Polerovirus and Totivirus. Based on the genome of GDLZ isolate, seven specific primers (Table S1) were designed to amplify the full viral genomic sequences using a PrimeScriptTM One-Step RT-PCR Kit. Seven expected amplicons were obtained, cloned, and sequenced. The complete genome was determined to be 6,423 nucleotides (GenBank accession number OR854819) in length and designated as LNMJ isolate. LNMJ shared 96.8%-99.7% nucleotide sequence identities with CGMMV isolates from China. Phylogenetic analysis based on the complete genome sequences showed that LNMJ clustered together with CGMMV isolates hn (GenBank accession number KC851866), GDLZ (GenBank accession number MK933286), and JD8 (GenBank accession number KM873784) from China. The specific primers LM-TJ-3F/3R were designed to determine the virus-symptom association for LNMJ, and all twelve symptomatic C. rostellatum plants collected from fields tested positive for LNMJ. Two out of six randomly selected aphids from the diseased plants also tested positive. To further prove its infectivity, LNMJ was inoculated mechanically onto ten healthy Nicotiana benthamiana plants, and the results indicated a high infection rate of 80% (8/10), at 30 days post-inoculation despite no distinct symptoms observed. To our knowledge, this is the first report of the natural infection of C. rostellatum plants with CGMMV. C. rostellatum is a widespread herb in China (Wei et al., 2019) and more surveys are needed to determine the distribution of CGMMV. The habitats of C. rostellatum span diverse agroecological zones, and thus our study underscores the potential spillover of CGMMV to neighboring crops as a significant risk.

Insights into the effects of coating and single crystallization on the rate performance and cycle life of LiNi0.9Mn0.1O2 cathode.

Coating and single crystal are two common strategies for cobalt-free nickel-rich layered oxides to solve its poor rate performance and cycle stability. However, the action mechanism of different modification protocols to suppress the attenuation are unclear yet. Herein, the Li2MoO4 layer-coated polycrystalline LiNi0.9Mn0.1O2 (1.0 %-Mo + NM91) and single crystal LiNi0.9Mn0.1O2 (SC-NM91) are prepared to investigate this difference, respectively. By focusing on the interior of particles, the relationship between structure evolution and electrochemical behavior is systematically studied, and the intrinsic mechanism of coating/single-crystallization modifications on suppressing the attenuation is clarified. The results show that microcracks in LiNi0.9Mn0.1O2 (NM91) are the main culprit leading to the rate capability decay, and the coating can effectively prevent the radial diffusion of microcracks from the center to surface, inhibiting the generation of surface side reactions. Therefore, the coating has a more advantage in improving the rate performance at 5.0C, the discharge capacity of 1.0 %-Mo + NM91 (130.6 mAh/g) is 7.9 % higher than that of SC-NM91 (121.0 mAh/g). In contrast, the single-crystallization can effectively prevent the formation of intergranular cracks arising from the anisotropic stress in NM91, which causes the severe cycle degradation. Correspondingly, the grain boundary-free SC-NM91 shows superior cyclability. The capacity retention rate of SC-NM91 (80.8 %) at 0.2C after 100cycles is 6.3 % higher than that of 1.0 %-Mo + NM91 (74.5 %). This work concludes the effect difference of different modification methods on enhancing the electrochemical performance, which provides theoretical and technical guidance for the optimized and targeted modification design in the cobalt-free high nickel cathode materials.