Naslov
Short-term salt stress in Brassica rapa seedlings causes alterations in auxin metabolism

Autori
Pavlović, Iva ; Pěnčík, Aleš ; Novák, Ondřej ; Vujčić, Valerija ; Radić Brkanac, Sandra ; Lepeduš, Hrvoje ; Strnad, Miroslav ; Salopek-Sondi, Branka

Izvornik
Plant physiology and biochemistry (0981-9428) 125 (2018); 74-84

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
auxin metabolism ; Brassica rapa ssp. pekinensis ; growth inhibition ; reactive oxygen species ; short-term salinity stress ; stress hormones ; principal component analysis

Sažetak
Salinity is one of major abiotic stresses affecting Brassica crop production. Here we present investigations into the physiological, biochemical, and hormonal components of the short-term salinity stress response in Chinese cabbage seedlings, with particular emphasis on the biosynthesis and metabolism of auxin indole-3-acetic acid (IAA). Upon salinity treatments (50- 200 mM NaCl) IAA level was elevated in a dose dependent manner reaching 1.3-fold increase at the most severe salt treatment in comparison to the control. IAA precursor profiling suggested that salinity activated the indole-3-acetamide and indole-3-acetaldoxime biosynthetic pathways while suppressing the indole-3-pyruvic acid pathway. Levels of the IAA catabolites 2-oxoindole-3-acetic acid and indole-3-acetic acid-aspartate increased 1.7- and 2.0-fold, respectively, under the most severe treatment, in parallel with those of IAA. Conversely, levels of the ester conjugate indole-3-acetyl-1-O-ß-d-glucose and its catabolite 2-oxoindole-3-acetyl-1-O-ß-d-glucose decreased 2.5- and 7.0-fold, respectively. The concentrations of stress hormones including jasmonic acid and jasmonoyl-isoleucine (JA and JA-Ile), salicylic acid (SA) and abscisic acid (ABA) confirmed the stress induced by salt treatment: levels of JA and JA-Ile increased strongly under the mildest treatment, ABA only increased under the most severe treatment, and SA levels decreased dose-dependently. These hormonal changes were related to the observed changes in biochemical stress markers upon salt treatments: reductions in seedling fresh weight and root growth, decreased photosynthesis rate, increased levels of reactive oxygen species, and elevated proline content and the Na+/K+ ratio. Correlations among auxin profile and biochemical stress markers were discussed based on Pearson’s coefficients and principal component analysis (PCA).

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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