New Scientist has an article entitled “Fungus-powered superplants may beat the heat” on how endophytic fungi from thermotollerant grass – Dichanthelium lanuginosum – can be used to improved drought-, salt-, and cold- tolerance of many other plants including rice. This symbiosis of the endophyte and grass also has additional player in the form of a mycovirus that infects the fungus which we’ve talked about before. The article doesn’t seem to reference any recently published papers but mainly the ongoing work for field trials and the application of these endophytes to speed the adaptations of the plants.
This complicated partnership is a fascinating example of the complex strategies that have evolved among these organisms as part of colonization of new niches. It is also quite likely, they are along for the ride in most plant systems and we are just now beginning to see their diversity and function.
Genome Technology highlights the very cool thing about next-gen sequencing – it puts the power in the hands of the researchers to explore genome sequence and doesn’t limit them to projects only funded through sequencing centers. The Genome Technology piece highlights work at Duke to sequence the genome Cladonia grayi, a lichenized fungus, with 454 technology at Duke’s Institute for Genome Sciences and Policy through their next-gen sequencing program. This is the way of the future where sequencing core facilities will be able to generate sequence only having to wait in the queue at the own university rather than through community sequencing project or sequencing center proposal queues.
This isn’t the only lichen being sequenced. Xanthoria parietina is also in the queue at JGI, but has taken a while to get going because of some logistical problems getting the DNA (and any problems are amplified because it takes a long time to get new material since lichens grow very slow).
The transfer of the power for researchers to be able to quick exploratory whole-genome sequencing with next-gen and eventually, high quality genome sequences from next-gen sequencing is predicted to transform how this kind of science gets done. It means we’ll probably just sequence a mutant strain instead of trying to map the mutation – this is happening already in anecdotal stories in worms and in our work in mushrooms. N.B. this is done after a mutagenized strain has been cleaned up a bit to insure we’re looking for one or only a few mutations based on some crosses – but that is part of standard genetic approaches anyways.
This fast,cheap,whole-genome-sequencing is also the stuff of personal genomics, but for basic research it will also mean that a first pass exploring gene repertoire of an organism will be a multi-week instead of multi-year project. I just hope we’re training enough people who can efficiently extract the information from all this data with solid bioinformatics, computational, data-oriented programming, and statistical skills to support all the labs that will want to take this approach. You’ll need a life-vest to swim in the big data pool for a while until more tools are developed that can be deployed by non-experts.
Today, I would like to share the news about the publication of the Laccaria bicolor genome. This is the first mycorrhizal symbiotic genome published in the Nature journal. The title is “The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis”.
The team consisteing of more than 60 researchers from 16 institutions have revealed the interaction between plant and fungi.
For complete publication and additional news.
I read this blurb in the New Scientist about a PNAS paper (subscription required for next 6 months) on how hive beetles (Aethina tumida) are able to infest bee hives by throwing off the bees because they are producing isopentyl acetate which is thought to be produced and used by bees to signal an alarm. So the increased levels of the pheromone disorients the bees allowing beetles to continue infecting. European bees appear to be susceptible to this attack while the African bees have apparently evolved to better handle the beetle infestation. I’m not clear if the African bees have a different behavior or if they have different biochemical pathways/receptors to not be fooled by the cheap perfume of the invaders.
The fungus part here is that the beetles are carrying a hemiascomycete yeast, Kodamaea ohmeri in the Saccharomyces clade (see Suh and Blackwell 2005 for more details), which produces the isopentyl acetate pheromone. So it is a sort of auto-immune hive reaction where the defense mechanism is being short-circuited and harming the host.
Continue reading Would a Beetle by another name smell as sweet?
A paper in Nature this week describes how a few mutations can alter the interactions between species in a biofilm from competitive to cooperative system. This is a great study that goes from start to finish on studying community interactions, looking at an evolved phenotype, and understanding the genetic and physiological basis for the adaptation.
Acinetobacter sp. and Pseudomonas putida were raised in a carbon-limited environment with only benzyl alcohol as the carbon source. Acinetobacter can processes the benzyl alcohol, while P. putida is unable to. Acinetobacter takes up the bezyl alcohol and secretes benzoate that P. putida can then use as a carbon source. The research group propagated these in chemostats and looked at different starting concentrations of the organisms. They found that evolved P. putida had a different morphology and did several experiments to determine the relative fitness of the derived and ancestral genotype.
They went on to also map the mutations in P. putida and found two independent mutations in wapH (I think this is the right gene)â€”a gene involved in lipopolysaccharide (LPS) biosynthesis. They then engineered the ancestral strain to have a mutation in P. putida and found the rough colony phenotype morphology indistinguishable from the strain derived from experimental evolution.
There are various evolutionary and niche adaptation implications arising from this study. One application to mycology is to how lichens evolved in that an algael cell and a fungal cell must communicate and cooperate.
Ants, fungi, and bacteria
I have to admit that I am fascinated by co-evolution of symbiotic and mutalistic systems. A review by Richard Robinson gives an overview. A great example is the mutalism between ants and fungi where the ants cultivate the fungi for food. There are more layers to the relationship as a fungal parasite (Escovopsis) attacks the cultivated fungi, and a bacteria. Several researchers have studied the coevolution of these studies including Ulrich Mueller and Cameron Currie. Currie and Mueller have published several great studies describing the patterns of coevolution and the nature of the cooperation.
Continue reading Tripartate symbioses with fungi