Insight into phytohormonal modulation of defense mechanisms to salt excess in a halophyte and a glycophyte from Asteraceae family

• Published in: Plant and soil Vol. 463; no. 1-2; pp. 55 - 76
• Main Authors: Wiszniewska, Alina, Koźmińska, Aleksandra, Hanus-Fajerska, Ewa, Dziurka, Kinga, Dziurka, Michał
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-06-2021; Springer; Springer Nature B.V
• Subjects: Abscisic acid; Analysis; Antioxidants; Benzoic acid; Betaine; Betaines; Biomedical and Life Sciences; Carbohydrates; Comparative analysis; Compositae; Defense mechanisms; Defense reaction (Physiology); Ecology; Growth regulators; Halophytes; Homeostasis; Identification and classification; Jasmonic acid; Life Sciences; Mannitol; Oxidative stress; Plant growth; Plant hormones; Plant Physiology; Plant Sciences; Proline; Regular Article; Salicylic acid; Salinity; Salinity effects; Salinity tolerance; Salt tolerance; Soil salinity; Soil Science & Conservation; Soils; Soils, Salts in; Species; Sucrose; Poland; Antioxidants; Salt excess; Extremophyte; Relative taxa; Phytohormones; Ions; Osmolytes
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-021-04889-x

Aims
The aim of this study was to compare the efficiency of three defense mechanisms (ionic balance, osmotic adjustment and counteracting oxidative stress) under low, moderate and high soil salinity in two related species of contrasting tolerance to salinity: the halophyte
Aster tripolium
and the glycophyte
Aster alpinus
, and to elucidate their phytohormone-mediated regulation.
Methods
The phytohormonal profiling was performed to asses correlations between the pool of plant growth regulators and parameters depicting ionic homeostasis, osmotic adjustment and antioxidant system.
Results
Defense mechanisms in both species were based on accumulation/activity of distinct compounds (Na
+
and K
+
ions, antioxidants), but differences among species concerned particularly soluble carbohydrates and betaines. The halophyte accumulated mannitol, uronic acids and sucrose, while the glycophyte mostly glucose and proline-betaine. The halophyte responses also correlated with changes in the content of plant growth promoting PGRs, as well as jasmonates and benzoic acid. The glycophyte responses corresponded with changes in content of abscisic acid and ethylene precursor, as well as salicylic acid.
Conclusions
We provided evidence that benzoic acid rather than salicylic acid is involved in salt tolerance in the halophyte and elevated SA content may enhance vulnerability to salt excess. An important element of tolerance trait is also JA-GA network that influences the intensity of defense responses. This study uncovers new aspects of internal phytohormonal regulation of plant reaction to soil salinity and enables further insight into extremophyte biology.