Transcriptomics-based analysis using RNA-Seq of the coconut (Cocos nucifera) leaf in response to yellow decline phytoplasma infection

Invasive phytoplasmas wreak havoc on coconut palms worldwide, leading to high loss of income, food insecurity and extreme poverty of farmers in producing countries. Phytoplasmas as strictly biotrophic insect-transmitted bacterial pathogens instigate distinct changes in developmental processes and defence responses of the infected plants and manipulate plants to their own advantage; however, little is known about the cellular and molecular mechanisms underlying host–phytoplasma interactions. Further, phytoplasma-mediated transcriptional alterations in coconut palm genes have not yet been identified. This study evaluated the whole transcriptome profiles of naturally infected leaves of Cocos nucifera ecotype Malayan Red Dwarf in response to yellow decline phytoplasma from group 16SrXIV, using RNA-Seq technique. Transcriptomics-based analysis reported here identified genes involved in coconut innate immunity. The number of down-regulated genes in response to phytoplasma infection exceeded the number of genes up-regulated. Of the 39,873 differentially expressed unigenes, 21,860 unigenes were suppressed and 18,013 were induced following infection. Comparative analysis revealed that genes associated with defence signalling against biotic stimuli were significantly overexpressed in phytoplasma-infected leaves versus healthy coconut leaves. Genes involving cell rescue and defence, cellular transport, oxidative stress, hormone stimulus and metabolism, photosynthesis reduction, transcription and biosynthesis of secondary metabolites were differentially represented. Our transcriptome analysis unveiled a core set of genes associated with defence of coconut in response to phytoplasma attack, although several novel defence response candidate genes with unknown function have also been identified. This study constitutes valuable sequence resource for uncovering the resistance genes and/or susceptibility genes which can be used as genetic tools in disease resistance breeding.

Cocos Malay language since integration with Australia

The Cocos (Keeling) Islands are a remote Australian territory in the Indian Ocean and arehome to the Cocos Malay people, who have developed a distinct dialect. It waspredicted over 30 years ago that the Cocos Malay language faced extinction, perhapseven within the timeframe of one generation. Two possible threats to the Cocos Malaylanguage were identified. It was felt that English, as the language of power, may replacethe Cocos Malay language. The other possibility was language convergence, whereCocos Malay would be subsumed by another, larger Malay dialect. With these issues inmind, I explore developments in the Cocos Malay language since the Islands’ fullintegration with Australia in 1984. Drawing from extensive ethnographic work andlinguistic research into Cocos Malay I also refer to the work of other researchers toanalyse how the Cocos Malay language has developed over the past 30 years, in a timeof great social change. I argue that integration with Australia and attempts atassimilation have resulted in social dynamics where Cocos Malay language remains adefining marker of Cocos Malay identity positioning. In this social environment, CocosMalay therefore remains viable and, despite language change, does not face immediateextinction.

Response to long-distance relocation in Asian elephants (Elephas maximus) : monitoring adrenocortical activity via serum, urine, and feces

Understanding how elephants respond to potentially stressful events, such as relocation, is important for making informed management decisions. This study followed the relocation of eight Asian elephants from the Cocos (Keeling) Islands to mainland Australia. The first goal of this study was to examine patterns of adrenocortical activity as reflected in three different substrates: serum, urine, and feces. We found that the three substrates yielded very different signals of adrenocortical activity. Fecal glucocorticoid metabolites (FGM) increased as predicted post-transport, but urinary glucocorticoid metabolites (UGM) were actually lower following transport. Serum cortisol levels did not change significantly. We suggest that the differences in FGM and UGM may reflect changes in steroid biosynthesis, resulting in different primary glucocorticoids being produced at different stages of the stress response. Additional studies are needed to more thoroughly understand the signals of adrenocortical activity yielded by different substrates. The second goal was to examine individual variation in patterns of adrenal response. There was a positive correlation between baseline FGM value and duration of post-transfer increase in FGM concentration. Furthermore, an individual's adrenocortical response to relocation was correlated with behavioral traits of elephants. Elephants that were described by keepers as being “curious” exhibited a more prolonged increase in FGM post-transfer, and “reclusive” elephants had a greater increase in FGM values. Future research should investigate the importance of these personality types for the management and welfare of elephants.