Case study for oxalate and its related mineral contents in selected fodder plants in subtropical and tropical regions

A survey of oxalate and its related mineral contents in selected fodder plants was conducted in two regions of subtropical Okinawa, Japan and of tropical Savar and Shahzadpur, Bangladesh. A total of 31 samples were taken from 13 fodder species in Okinawa, Southern part of Japan and of 63 samples from 27 fodder species in Bangladesh. The data of both regions revealed that the majority of fodder plants accumulated lower contents of oxalate than the critical level for toxicity at more than 20 g kg-1 DM, while few fodder species (Pennisetum purpureum and Brachiaria mutica) in Bangladesh and only Setaria sphacelatain southern part of Japan reached this critical level. In most of the cases, no relationship was found between oxalate and mineral contents in the plants tested. The results from the present study demonstrate that the oxalate content in tropical fodder species may vary in a wide range, mainly depending on plant species. To be noted is that some fodder species could accumulate oxalate at so high content as might be toxic to ruminants in certain conditions. © 2013 Academic Journals Inc

A bioinformatics approach to distinguish plant parasite and host transcriptomes in interface tissue by classifying RNA-Seq reads

BACKGROUND: The genus Cuscuta is a group of parasitic plants that are distributed world-wide. The process of parasitization starts with a Cuscuta plant coiling around the host stem. The parasite’s haustorial organs then establish a vascular connection allowing for access to the phloem content. The host and the parasite form new cellular connections, suggesting coordination of developmental and biochemical processes. Simultaneous monitoring of gene expression in the parasite’s and host’s tissues may shed light on the complex events occurring between the parasitic and host cells and may help to overcome experimental limitations (i.e. how to separate host tissue from Cuscuta tissue at the haustorial connection). A novel approach is to use bioinformatic analysis to classify sequencing reads as either belonging to the host or to the parasite and to characterize the expression patterns. Owing to the lack of a comprehensive genomic dataset from Cuscuta spp., such a classification has not been performed previously. RESULTS: We first classified RNA-Seq reads from an interface region between the non-model parasitic plant Cuscuta japonica and the non-model host plant Impatiens balsamina. Without established reference sequences, we classified reads as originating from either of the plants by stepwise similarity search against de novo assembled transcript sets of C. japonica and I. balsamina, unigene sets of the same genus, and cDNA sequences of the same family. We then assembled de novo transcriptomes from the classified read sets. We assessed the quality of the classification by mapping reads to contigs of both plants, achieving a misclassification rate low enough (0.22-0.39%) to be used reliably for differential gene expression analysis. Finally, we applied our read classification method to RNA-Seq data from the interface between the non-model parasitic plant C. japonica and the model host plant Glycine max. Analysis of gene expression profiles at 5 parasitizing stages revealed differentially expressed genes from both C. japonica and G. max, and uncovered the coordination of cellular processes between the two plants. CONCLUSIONS: We demonstrated that reliable identification of differentially expressed transcripts in undissected interface region of the parasite-host association is feasible and informative with respect to differential-expression patterns. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13007-015-0066-6) contains supplementary material, which is available to authorized users