Drought-Induced Responses of Physiology, Metabolites, and PR Proteins in Triticum aestivum.
The impact of severe drought stress (13% soil moisture) on the physiological responses, metabolic profile, and pathogenesis-related (PR) proteins in wheat above- and below-ground biomass after 20 days of treatment was studied. Drought depleted growth, assimilation pigments, and majority of free amino acids in the shoots (but proline increased considerably, +160%). On the contrary, root growth parameters were elevated, and free amino acids did not decrease, indicating investment of metabolites into the growth of roots under water deficiency. Mineral nutrients were only slightly influenced. Profiling of pathogenesis-related (PR) proteins revealed that chitinases (EC 3.2.1.14) and glucanases (EC 3.2.1.39) were activated in wheat by drought. Individual isoforms and their activity were rather stimulated under drought, especially in shoots. The expression of selected genes is in agreement with enzymatic data and suggests an organ (tissue) specific- and opposing behavior of these two types of defense components in drought-stressed wheat. Metabolic analyses at the level of phenolics showed an increase in the free and bound fraction of phenolic acids almost exclusively in the shoots and flavonoid isoorientin increased considerably: protective action against oxidative stress and dehydration of the leaves seems to be the main reason for this finding. The role of PR proteins and phenolics in drought-stressed tissue is discussed.
Faculty of Natural Sciences, Department of Botany and Genetics, Constantine the Philosopher University , Nábrežie mládeže 91, 949 74 Nitra, Slovak Republic.
Zuzana
Z
Gregorová
Jozef
J
Kováčik
Bořivoj
B
Klejdus
Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences , Akademická 2, P.O. Box 39A, 950 07 Nitra, Slovak Republic.
Marína
M
Maglovski
Faculty of Natural Sciences, Department of Botany and Genetics, Constantine the Philosopher University , Nábrežie mládeže 91, 949 74 Nitra, Slovak Republic.
Roman
R
Kuna
National Agricultural and Food Centre - Research Institute of Plant Production, Bratislavská cesta 122, 921 68 Piešt'any, Slovak Republic.
Pavol
P
Hauptvogel
Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences , Akademická 2, P.O. Box 39A, 950 07 Nitra, Slovak Republic.
Ildikó
I
Matušíková
D000596:Amino Acids / Q000032:analysis; D002688:Chitinases / Q000378:metabolism; D055864:Droughts; D004789:Enzyme Activation / Q000502:physiology; D006026:Glycoside Hydrolases / Q000378:metabolism; D062385:Hydroxybenzoates / Q000032:analysis; D047311:Luteolin / Q000032:analysis; D055442:Metabolome; D010940:Plant Proteins / Q000032:analysis*; D018517:Plant Roots / Q000254:growth & development; D018520:Plant Shoots / Q000737:chemistry / Q000201:enzymology / Q000254:growth & development; D013312:Stress, Physiological / Q000502:physiology*; D014908:Triticum / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D014867:Water
D000596:Amino Acids; D062385:Hydroxybenzoates; D010940:Plant Proteins; D014867:Water; C057912:homoorientin; D006026:Glycoside Hydrolases; D002688:Chitinases; C017616:phenolic acid; D047311:Luteolin
abiotic stress; antioxidants; enzymes; metabolome; soil limitation