| Full text | |
| Author(s): |
Boava, Leonardo Pires
;
Cristofani-Yaly, Mariangela
;
Machado, Marcos Antonio
Total Authors: 3
|
| Document type: | Journal article |
| Source: | PHYTOPATHOLOGY; v. 107, n. 5, p. 10-pg., 2017-05-01. |
| Abstract | |
Huanglongbing (HLB) is a destructive disease of citrus caused by phloem-limited bacteria, namely 'Candidatus Liberibacter asiaticus' (Las), 'Candidatus Liberibacter africanus', and 'Candidatus Liberibacter americanus'. Although there are no known HLB-resistant citrus species, studies have reported Poncirus trifoliata as being more tolerant. Assuming that callose deposition in the phloem of infected plants can inhibit translocation of photosynthetic products and cause starch accumulation, we compared callose deposition in petioles and starch accumulation in infected leaves of three genotypes (Citrus sinensis, C. sunki, and P. trifoliata) and 15 hybrids (C. sunki x P. trifoliata). Compared with the mock-inoculated plants, higher bacterial counts and greater accumulation of callose and starch were found in C. sinensis, C. sunki, and 10 of the hybrid plants. Lower titer and fewer metabolic changes due to Las infection were observed in P. trifoliata and in two Las-positive hybrids while three hybrids were Las-negative. Callose accumulation was linked to and correlated with genes involved in phloem functionality and starch accumulation was linked to up-regulation of genes involved in starch biosynthesis and repression of those related to starch breakdown. Lower expression of genes involved in phloem functionality in resistant and tolerant plants can partially explain the absence of distinct disease symptoms associated with starch accumulation that are usually observed in HLB-susceptible genotypes. (AU) | |
| FAPESP's process: | 12/01917-2 - Functional genomics and genetic mapping of new citrus hybrids tolerant to huanglongbing (HLB or greening) |
| Grantee: | Leonardo Pires Boava |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 11/18605-0 - Obtaining and evaluation of new varieties of scion and rootstock for citrus |
| Grantee: | Mariângela Cristofani-Yaly |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 07/08435-5 - Disease resistance in citrus: genetic mapping and functional genomics of new hybrids |
| Grantee: | Mariângela Cristofani-Yaly |
| Support Opportunities: | Regular Research Grants |