Evaluation of banana cultivars and the pathogenesis-related class 3 and 10 proteins in defense against Ralstonia syzygii subsp. celebesensis, the causal agent of banana blood disease

Banana blood disease (BBD), caused by Ralstonia syzygii subsp. celebesensis ( Rsc), is a major threat to banana production in Southeast Asia. This study aimed to assess the resistance of cultivated and wild banana accessions to Rsc and investigate the expression of pathogenesis- related (PR) protein genes, namely PR3 and PR10, in disease-resistant bananas. Bacterial isolates were isolated from infected bananas in Yala Province, Thailand, and their pathogenicity and phylotype were confirmed, along with Rsc-specific PCR. Rsc-resistance banana screening was conducted on 16 banana accessions, including cultivated and wild types, using representative Rsc isolates. ‘Khai Kasetsart 2’ exhibited resistance (R), followed by ‘Raksa’ with moderate resistance (MR). The expression of PR3 and PR10 genes was analyzed in the resistant ‘Khai Kasetsart 2’ and susceptible ‘Hin’ bananas, revealing distinct expression patterns. PR3 showed rapid upregulation on day 1 after inoculation (DAI), while PR10 exhibited sustained upregulation from 1 to 7 DAI in the resistant cultivar. These findings indicate the involvement of PR proteins in the defense response against Rsc and hold promise for future breeding and disease management strategies in bananas

Refinement of the taxonomic structure of 16SrXI and 16SrXIV phytoplasmas of gramineous plants using multilocus sequence typing

Phytoplasmas that infect gramineous plants, including Napier grass stunt, sugarcane whiteleaf, sugarcane grassy shoot, and Bermuda grass whiteleaf, have been classified into two closely related groups, 16SrXI and 16SrXIV, based on the 16S ribosomal RNA (rRNA) gene. Subsequently, phytoplasmas associated with coconut and Areca palm in southern India and Sri Lanka have been added into the 16SrXI group. However, the 16S rRNA gene gives relatively poor resolution between these phytoplasmas. In this study, a new set of universal phytoplasma primers that amplify approximately 1 kb of the leucyl transfer RNA synthetase (leuS) gene have been validated on a broad range of phytoplasma taxonomic groups. These have been used along with partial sequences of the secA gene to clarify the taxonomic classification of 16SrXI and 16SrXIV phytoplasmas. Based on this data, the sugarcane whiteleaf and grassy shoot phytoplasmas appear to be the same phytoplasma. The Napier grass stunt phytoplasma forms a distinct group from the Bermuda grass whiteleaf and sugarcane phytoplasmas, suggesting that Napier grass stunt should be in its own ‘Candidatus Phytoplasma sp.’. The phytoplasmas associated with coconut and arecanut in southern India and Sri Lanka, which are in the same 16SrXI group, appear in different groups based on secA analysis

Draft Genome Sequence of "Candidatus Phytoplasma oryzae" Strain Mbita1, the Causative Agent of Napier Grass Stunt Disease in Kenya.

Phytoplasmas are bacterial plant pathogens with devastating impact on agricultural production worldwide. In eastern Africa, Napier grass stunt disease causes serious economic losses in the smallholder dairy industry. This draft genome sequence of " ITALIC! CandidatusPhytoplasma oryzae" strain Mbita1 provides insight into its genomic organization and the molecular basis of pathogenicity

Grafting Compatibility, Scion Growth, and Fusarium Wilt Disease Incidence of Intraspecific Grafted Tomato

The tomato (Solanum lycopersicum L.) is one of the most important vegetables grown globally. However, the production of tomatoes is restricted by Fusarium oxysporum f. sp. lycopersici (Fol). This study aims to investigate the ability of Fol-resistant tomato genotypes to be a rootstock for the susceptible cultivar. In this study, a tomato cultivar was grafted on rootstocks of the same species (intraspecific), and grafting compatibility, peroxidase gene expression, and fusarium wilt disease incidence of tomato scion was evaluated. A Fol-susceptible tomato ‘Sidathip 3’ (SDT3) was grafted onto four different Fol-resistant tomato genotypes and compared with self-grafted cultivar/cultivar and rootstock/rootstock. The survival rate of all grafted plants was 100% at 20 days after grafting (DAG) without significant differences in incompatibility evaluated at 42 days after grafting. The expression of the peroxidase gene (Solyc02g084800.2) using the qPCR technique was compared in self-grafted rootstock LE472/LE472 and SDT3/LE472. The expression level was three times higher in heterografted plants than in self-grafted ones at 15 DAG, indicating graft incompatibility. The rootstocks did not affect the height of the plant, the number of branches, the size of the fruit, or the yield of SDT3 scion. All intraspecific heterografted plants significantly controlled Fol when evaluated 60 days after inoculation. These results showed the usefulness of intraspecific grafting by using the proper rootstock genotypes to increase pathogen resistance in addition to stimulating growth and fruit yield

Draft Genome Sequence of “ Candidatus

Phytoplasmas are bacterial plant pathogens with devastating impact on agricultural production worldwide. In eastern Africa, Napier grass stunt disease causes serious economic losses in the smallholder dairy industry. This draft genome sequence of " ITALIC! CandidatusPhytoplasma oryzae" strain Mbita1 provides insight into its genomic organization and the molecular basis of pathogenicity

Draft Genome Sequence of “ Candidatus Phytoplasma oryzae” Strain Mbita1, the Causative Agent of Napier Grass Stunt Disease in Kenya

Phytoplasmas are bacterial plant pathogens with devastating impact on agricultural production worldwide. In eastern Africa, Napier grass stunt disease causes serious economic losses in the smallholder dairy industry. This draft genome sequence of “ Candidatus Phytoplasma oryzae” strain Mbita1 provides insight into its genomic organization and the molecular basis of pathogenicity