title: Transcriptional responses indicate maintenance of photosynthetic proteins as key to the exceptional chilling tolerance of C4 photosynthesis in Miscanthus × giganteus.
abstract: Miscanthus × giganteus is exceptional among C4 plants in its ability to acclimate to chilling (≤14 °C) and maintain a high photosynthetic capacity, in sharp contrast to maize, leading to very high productivity even in cool temperate climates. To identify the mechanisms that underlie this acclimation, RNA was isolated from M × giganteus leaves in chilling and nonchilling conditions and hybridized to microarrays developed for its close relative Zea mays. Among 21 000 array probes that yielded robust signals, 723 showed significant expression change under chilling. Approximately half of these were for annotated genes. Thirty genes associated with chloroplast membrane function were all upregulated. Increases in transcripts for the lhcb5 (chlorophyll a/b-binding protein CP26), ndhF (NADH dehydrogenase F, chloroplast), atpA (ATP synthase alpha subunit), psbA (D1), petA (cytochrome f), and lhcb4 (chlorophyll a/b-binding protein CP29), relative to housekeeping genes in M. × giganteus, were confirmed by quantitative reverse-transcription PCR. In contrast, psbo1, lhcb5, psbA, and lhcb4 were all significantly decreased in Z. mays after 14 days of chilling. Western blot analysis of the D1 protein and LHCII type II chlorophyll a/b-binding protein also showed significant increases in M. × giganteus during chilling and significant decreases in Z. mays. Compared to other C4 species, M. × giganteus grown in chilling conditions appears to counteract the loss of photosynthetic proteins and proteins protecting photosystem II typically observed in other species by increasing mRNA levels for their synthesis.
authors: Proctor and Gamble, 8700 South Mason-Montgomery Road Mason, OH 45040, USA.
authors: Ashley K
authors: AK
authors: Spence
authors: Department of Crop Sciences, University of Illinois, 389 Edward R. Madigan Laboratory, 1201W Gregory Drive, Urbana, IL 61801, USA.
authors: Jay
authors: J
authors: Boddu
authors: Monsanto Company, Chesterfield Village Research Center, 700 Chesterfield Parkway North, Chesterfield, MO 63017, USA.
authors: Dafu
authors: D
authors: Wang
authors: Department of Crop Sciences, University of Illinois, 389 Edward R. Madigan Laboratory, 1201W Gregory Drive, Urbana, IL 61801, USA.
authors: Brandon
authors: B
authors: James
authors: Energy Biosciences Institute, University of Illinois, 1200 Institute for Genomic Biology, 1206W. Gregory Drive, Urbana, IL 61801, USA.
authors: Kankshita
authors: K
authors: Swaminathan
authors: Department of Crop Sciences, University of Illinois, 389 Edward R. Madigan Laboratory, 1201W Gregory Drive, Urbana, IL 61801, USA.
authors: Stephen P
authors: SP
authors: Moose
authors: Department of Crop Sciences, University of Illinois, 389 Edward R. Madigan Laboratory, 1201W Gregory Drive, Urbana, IL 61801, USA slong@illinois.edu.
authors: Stephen P
authors: SP
authors: Long
mesh_terms: D000222:Adaptation, Physiological; D002245:Carbon Dioxide / Q000378:metabolism*; D061146:Chlorophyll Binding Proteins / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008027:Light; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D006109:Poaceae / Q000235:genetics* / Q000502:physiology / Q000528:radiation effects; D018749:RNA, Plant / Q000235:genetics; D003313:Zea mays / Q000235:genetics / Q000502:physiology
chemical_list: D061146:Chlorophyll Binding Proteins; D045332:Photosystem II Protein Complex; D018749:RNA, Plant; D002245:Carbon Dioxide
keywords: C4 photosynthesis; D1 protein; LHCII; Miscanthus; chilling; chlorophyll a/b-binding protein; cold; low temperature; maize; transcription.