TY - JOUR
T1 - Physiological and molecular responses of the isoprenoid biosynthetic pathway in a drought-resistant Mediterranean shrub, Cistus creticus exposed to water deficit
AU - Munné-Bosch, Sergi
AU - Falara, Vasiliki
AU - Pateraki, Irini
AU - López-Carbonell, Marta
AU - Cela, Jana
AU - Kanellis, Angelos K.
PY - 2009
Y1 - 2009
N2 - The goal of the present research was to obtain new insights into the mechanisms underlying drought stress resistance in plants. Specifically, we evaluated changes in the expression of genes encoding enzymes involved in isoprenoid biosynthesis, together with the levels of the corresponding metabolites (chlorophylls, carotenoids, tocopherols and abscisic acid), in a drought-resistant Mediterranean shrub, Cistus creticus grown under Mediterranean field conditions. Summer drought led to reductions in the relative leaf water content (RWC) by 25%, but did not alter the maximum efficiency of PSII, indicating the absence of damage to the photosynthetic apparatus. While the expression of genes encoding C. creticus chlorophyll a oxygenase/chlorophyll b synthase (CAO) and phytoene synthase (PSY) were not affected by water deficit, the genes encoding homogentisate phytyl-transferase (HPT) and 9-cis-epoxycarotenoid dioxygenase (NCED) were induced in water-stressed (WS) plants. Drought-induced changes in gene expression were observed at early stages of drought and were strongly correlated with levels of the corresponding metabolites, with simultaneous increases in abscisic acid and α-tocopherol levels of up to 4-fold and 62%, respectively. Furthermore, α-tocopherol levels were strongly positively correlated with abscisic acid contents, but not with the levels of jasmonic acid and salicylic acid. We conclude that the abscisic acid and tocopherol biosynthetic pathway may be regulated at the transcript level in WS C. creticus plants, and that the genes encoding HPT and NCED may play a key role in the drought stress resistance of this Mediterranean shrub by modulating abscisic acid and tocopherol biosynthesis.
AB - The goal of the present research was to obtain new insights into the mechanisms underlying drought stress resistance in plants. Specifically, we evaluated changes in the expression of genes encoding enzymes involved in isoprenoid biosynthesis, together with the levels of the corresponding metabolites (chlorophylls, carotenoids, tocopherols and abscisic acid), in a drought-resistant Mediterranean shrub, Cistus creticus grown under Mediterranean field conditions. Summer drought led to reductions in the relative leaf water content (RWC) by 25%, but did not alter the maximum efficiency of PSII, indicating the absence of damage to the photosynthetic apparatus. While the expression of genes encoding C. creticus chlorophyll a oxygenase/chlorophyll b synthase (CAO) and phytoene synthase (PSY) were not affected by water deficit, the genes encoding homogentisate phytyl-transferase (HPT) and 9-cis-epoxycarotenoid dioxygenase (NCED) were induced in water-stressed (WS) plants. Drought-induced changes in gene expression were observed at early stages of drought and were strongly correlated with levels of the corresponding metabolites, with simultaneous increases in abscisic acid and α-tocopherol levels of up to 4-fold and 62%, respectively. Furthermore, α-tocopherol levels were strongly positively correlated with abscisic acid contents, but not with the levels of jasmonic acid and salicylic acid. We conclude that the abscisic acid and tocopherol biosynthetic pathway may be regulated at the transcript level in WS C. creticus plants, and that the genes encoding HPT and NCED may play a key role in the drought stress resistance of this Mediterranean shrub by modulating abscisic acid and tocopherol biosynthesis.
KW - Abscisic acid
KW - Drought stress
KW - Gene expression
KW - Perennials
KW - Tocopherols
U2 - 10.1016/j.jplph.2008.02.011
DO - 10.1016/j.jplph.2008.02.011
M3 - Journal article
C2 - 18455260
AN - SCOPUS:57349128920
SN - 0176-1617
VL - 166
SP - 136
EP - 145
JO - Journal of Plant Physiology
JF - Journal of Plant Physiology
IS - 2
ER -