Only a single report mentions CLF symptoms on Hevea brasiliensis growing in the American continent (Junqueira et al. 1985). In this area, C. cassiicola remains benign on rubber trees but causes significant MM-102 solubility dmso damage to many other plant species. Could outbreaks of CLF disease occur in South American rubber plantations? To answer this question, we investigated whether previously undetected strains of the pathogen were present in rubber plantations in this area. The purpose FG-4592 price of our study was to test for
the presence of C. cassiicola among fungal rubber tree endophytes from a plantation in Brazil that had no history of the disease and to characterize these isolates. Material EPZ004777 nmr and methods Plant material Fungal endophytes were recovered from young Hevea brasiliensis trees in nurseries consisting of 10 different cultivars (CDC 312, CDC 1174, FDR 5240, FDR 5665, FDR 5788, GT 1, MDF 180, PB 260, PMB 1 and RRIM 600) from a rubber tree plantation in Bahia, Brazil. The plants used for the inoculation and gene expression experiments (cultivars RRIM 600 and FDR 5788) were cultivated in a greenhouse
in Clermont-Ferrand (France) at 28 °C ± 2 °C with 80 % relative humidity. All of the cultivars were grafted clones. Isolation of endophytic fungi from asymptomatic Brazilian rubber tree leaves Fungal endophytes were isolated from asymptomatic mature leaves that were
collected in the nurseries and kept at room temperature for 8 days. Leaf segments were surface-sterilized Endonuclease through sequential immersion in 70 % ethanol (1 min), 2 % sodium hypochlorite solution (2 min), 70 % (v/v) ethanol (30 s) and sterile water. Leaf pieces with freshly cut edges were plated on Malt Extract Agar (MEA) supplemented with 0.02 % chloramphenicol and placed at 25 °C in the dark. The emergent fungi were isolated by successive subcultures. Molecular identification of endophytic fungi All fungal isolates were grown from single conidia and verified by sequencing the internal transcribed spacer (ITS) region of the ribosomal DNA. For DNA extraction the isolates were grown on Potato Dextrose Agar (PDA) for 13 days in the dark. The mycelia was collected, frozen in liquid nitrogen and lyophilised. The genomic DNA was extracted as described previously (Risterucci et al. 2000). The ITS1, 5.8S, and ITS2 regions of the ribosomal DNA were amplified by PCR from 100 ng of genomic DNA in a 50 μl reaction mix containing 0.2 μM of the ITS1 and ITS4 primers (White et al. 1990), 200 μM of the dNTP mix, 2 mM of MgCl2, 1× buffer and 1 U of Taq DNA polymerase (Qbiogen, Illkirch, France). The PCR was conducted for 30 cycles under the following conditions: 45 s at 94 °C, 45 s at 55 °C and 45 s at 72 °C. The PCR products were sequenced by GATC Biotech (Konstanz, Germany).