MOLECULAR EFFECTS OF ENVIRONMENTAL CHANGES ON ANTARCTIC PLANTS TRANSCRIPTOME

Abstract

Open Top Chambers (OTCs) experiments have been widely used to assess warming effects on terrestrial plants, and to predict possible biological consequences of climate warming. Currently, King George Island of Antarctica Peninsula is one of the fastest warming regions on the planet. In that place, we installed OTCs in two sites, near to Arctowski station and compared the transcriptome changes of the only two Antarctic flowering plants, D. antarctica and C. quitensis growing inside and outside OTC. OTC experiments raised leaf temperatures by 2.72ºC and 0.38ºC for D. antarctica and C. quitensis, respectively, and air temperature by 1.37ºC on average from 10 Jan to 5 Mar, 2015. Plants for RNA extraction were sampled at the end of Feb, 2015. Compared to D. antarctica, C. quitensis has shown remarkable physiological enhancements in the relative growth, the net photosynthetic CO2 assimilation rate, and the dark respiration. Transcriptome analysis of C. quitensis growing inside and outside OTC revealed "Photosynthesis" was the most enriched functional GO term in OTC compared to the control, and "Response to stress" was the second. Otherwise, "Response to stress" was the most enriched functional GO term in OTC for D. antarctica. Additionally, several genes previously known to be related to control directly or indirectly photosynthetic activities, those encoding aquaporins, carbonic anhydrase, and Rubisco activase, were induced in C. quitensis from OTC. While, genes encoding aquaporins and Rubisco activase were induced from OTC, but carbonic anhydrase gene was not induced in D. antarctica implying that each plant species can adopt different strategy when facing the warming. Still we need invest much time and efforts to properly interpret the biological meaning, this report could be a bridge between physiological and transcriptome levels to predict changes of plants to climate warming in Antarctica.