Navegando por Autor "Carvalho, Flávia Maria de Souza"
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Item Detection and identification of Xanthomonas pathotypes associated with citrus diseases using comparative genomics and multiplex PCR.(2019) Fonseca, Natasha Peixoto; Felestrino, Érica Barbosa; Caneschi, Washington Luiz; Sanchez, Angelica Bianchini; Cordeiro, Isabella Ferreira; Lemes, Camila Gracyelle de Carvalho; Assis, Renata de Almeida Barbosa; Carvalho, Flávia Maria de Souza; Ferro, Jesus Aparecido; Varani, Alessandro de Mello; Belasque Junior, José; Setubal, João Carlos; Telles, Guilherme Pimentel; Aguena, Deiviston da Silva; Almeida Junior, Nalvo Franco de; Moreira, Leandro MarcioBackground. In Citrus cultures, three species of Xanthomonas are known to cause distinct diseases. X. citri subsp. citri patothype A, X. fuscans subsp. aurantifolii pathotypes B and C, and X. alfalfae subsp. citrumelonis, are the causative agents of cancrosis A, B, C, and citrus bacterial spots, respectively. Although these species exhibit different levels of virulence and aggressiveness, only limited alternatives are currently available for proper and early detection of these diseases in the fields. The present study aimed to develop a new molecular diagnostic method based on genomic sequences derived from the four species of Xanthomonas. Results. Using comparative genomics approaches, primers were synthesized for the identification of the four causative agents of citrus diseases. These primers were validated for their specificity to their target DNA by both conventional and multiplex PCR. Upon evaluation, their sensitivity was found to be 0.02 ng/µl in vitro and 1.5 × 104 CFU ml−1 in infected leaves. Additionally, none of the primers were able to generate amplicons in 19 other genomes of Xanthomonas not associated with Citrus and one species of Xylella, the causal agent of citrus variegated chlorosis (CVC). This denotes strong specificity of the primers for the different species of Xanthomonas investigated in this study. Conclusions. We demonstrated that these markers can be used as potential candidates for performing in vivo molecular diagnosis exclusively for citrus-associated Xanthomonas. The bioinformatics pipeline developed in this study to design specific genomic regions is capable of generating specific primers. It is freely available and can be utilized for any other model organism.Item Potential bioinoculants for sustainable agriculture prospected from ferruginous caves of the Iron Quadrangle/Brazil.(2021) Lemes, Camila Gracyelle de Carvalho; Cordeiro, Isabella Ferreira; Fernandes, Camila Henriques de Paula; Silva, Ana K.; Carmo, Flávio Fonseca do; Kamino, Luciana Hiromi Yoshino; Carvalho, Flávia Maria de Souza; Caicedo Cepeda, Juan Carlos; Ferro, Jesus Aparecido; Moreira, Leandro MarcioBiocontrol and plant growth-promoting bacteria (PGPB) are important agricultural bioinoc- ulants. This study aimed to prospect new potential bioinoculants for a more sustainable agriculture from ferruginous caves of the Brazilian Iron Quadrangle. Culturable bacteria, from seven caves and one canga soil sample, were evaluated for biocontroller activity of the phytopathogens Xanthomonas citri subsp. Citri—Xcc306 (citrus canker), Fusarium oxysporum—Fo (fusariosis), and Colletotrichum lindemuthianum—Cl89 (bean anthracnose). The ability of the superior candidates to solubilize inor- ganic phosphate, fix nitrogen, and produce hydrolytic enzymes and siderophores was then analyzed. Out of 563 isolates, 47 inhibited the growth of Xcc306 in vitro, of which 9 reduced citrus canker up to 68% when co-inoculated with the pathogen on host plants. Twenty of the 47 inhibited Fo growth directly by 51–73%, and 15 indirectly by 75–81%. These 15 inhibited Cl89 growth in vitro (up to 93% directly and 100% indirectly), fixed nitrogen, produced proteases and siderophores, showed motility ability, produced biofilm, and all but one solubilized inorganic phosphate. Therefore, 15 (2.66%) bacterial isolates, from the genera Serratia, Nissabacter, and Dickeya, act simultaneously as biocontrollers and PGPBs, and could be important candidates for future investigations in planta as an alternative to minimize the use of pesticides and chemical fertilizers through sustainable agricultural management practices.