Physiological and molecular adaptations to drought in Andean potato genotypes.
The drought stress tolerance of two Solanum tuberosum subsp. andigena landraces, one hybrid (adgxtbr) and Atlantic (S. tuberosum subsp. tuberosum) has been evaluated. Photosynthesis in the Andigena landraces during prolonged drought was maintained significantly longer than in the Tuberosum (Atlantic) line. Among the Andigena landraces, 'Sullu' (SUL) was more drought resistant than 'Negra Ojosa' (NOJ). Microarray analysis and metabolite data from leaf samples taken at the point of maximum stress suggested higher mitochondrial metabolic activity in SUL than in NOJ. A greater induction of chloroplast-localized antioxidant and chaperone genes in SUL compared with NOJ was evident. ABA-responsive TFs were more induced in NOJ compared with SUL, including WRKY1, mediating a response in SA signalling that may give rise to increased ROS. NOJ may be experiencing higher ROS levels than SUL. Metabolite profiles of NOJ were characterized by compounds indicative of stress, for example, proline, trehalose, and GABA, which accumulated to a higher degree than in SUL. The differences between the Andigena lines were not explained by protective roles of compatible solutes; hexoses and complex sugars were similar in both landraces. Instead, lower levels of ROS accumulation, greater mitochondrial activity and active chloroplast defences contributed to a lower stress load in SUL than in NOJ during drought.
Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA 24061, USA.
Cecilia
C
Vasquez-Robinet
Shrinivasrao P
SP
Mane
Alexander V
AV
Ulanov
Jonathan I
JI
Watkinson
Verlyn K
VK
Stromberg
David
D
De Koeyer
Roland
R
Schafleitner
David B
DB
Willmot
Merideth
M
Bonierbale
Hans J
HJ
Bohnert
Ruth
R
Grene
D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000222:Adaptation, Physiological; D004190:Disasters; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D008928:Mitochondria / Q000235:genetics / Q000502:physiology; D018832:Molecular Chaperones / Q000235:genetics; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D010788:Photosynthesis; D010940:Plant Proteins / Q000235:genetics; D011198:Solanum tuberosum / Q000235:genetics* / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics
D018528:ATP-Binding Cassette Transporters; D018832:Molecular Chaperones; D010940:Plant Proteins; D014157:Transcription Factors