title: Trehalose Accumulation Triggers Autophagy during Plant Desiccation.
abstract: Global climate change, increasingly erratic weather and a burgeoning global population are significant threats to the sustainability of future crop production. There is an urgent need for the development of robust measures that enable crops to withstand the uncertainty of climate change whilst still producing maximum yields. Resurrection plants possess the unique ability to withstand desiccation for prolonged periods, can be restored upon watering and represent great potential for the development of stress tolerant crops. Here, we describe the remarkable stress characteristics of Tripogon loliiformis, an uncharacterised resurrection grass and close relative of the economically important cereals, rice, sorghum, and maize. We show that T. loliiformis survives extreme environmental stress by implementing autophagy to prevent Programmed Cell Death. Notably, we identified a novel role for trehalose in the regulation of autophagy in T.loliiformis. Transcriptome, Gas Chromatography Mass Spectrometry, immunoblotting and confocal microscopy analyses directly linked the accumulation of trehalose with the onset of autophagy in dehydrating and desiccated T. loliiformis shoots. These results were supported in vitro with the observation of autophagosomes in trehalose treated T. loliiformis leaves; autophagosomes were not detected in untreated samples. Presumably, once induced, autophagy promotes desiccation tolerance in T.loliiformis, by removal of cellular toxins to suppress programmed cell death and the recycling of nutrients to delay the onset of senescence. These findings illustrate how resurrection plants manipulate sugar metabolism to promote desiccation tolerance and may provide candidate genes that are potentially useful for the development of stress tolerant crops.
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Brett
authors.initials: B
authors.lastname: Williams
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Isaac
authors.initials: I
authors.lastname: Njaci
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Lalehvash
authors.initials: L
authors.lastname: Moghaddam
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Hao
authors.initials: H
authors.lastname: Long
authors.affiliation: Department of Plant Pathology and Microbiology, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas, United States of America.
authors.forename: Martin B
authors.initials: MB
authors.lastname: Dickman
authors.affiliation: Department of Biochemistry and Biophysics, Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, Texas, United States of America.
authors.forename: Xiuren
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Sagadevan
authors.initials: S
authors.lastname: Mundree
mesh_terms: D001343:Autophagy / Q000235:genetics*; D057231:Climate Change; D032181:Craterostigma / Q000235:genetics / Q000254:growth & development*; D003890:Desiccation; D012275:Oryza; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D006109:Poaceae / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics; D059467:Transcriptome / Q000235:genetics*; D014199:Trehalose / Q000235:genetics / Q000378:metabolism*; D014867:Water
chemical_list: D014867:Water; D014199:Trehalose