The correlation analysis between phytohormones and metabolites
provides new insights for salinity studies
Hormones association with fatty acids may favour the protein lipid
modifications such as S-acylation and N-myristoylation, which correspond
to the irreversible link of lipid (fatty acid) to the N-terminal amino
acid residue of proteins. The lipid modification could be involved in
regulation of several biological processes redox homeostasis,
protein-membrane associations and protein stability under various
environmental stresses (Boyle et al., 2016; Majeran et al., 2018). The
exogenous application of MeJA on shoots of soybean showed increased
accumulation of cell wall SFAs to maintain growth under drought stress
(Mohamed & Latif, 2017). Further, JA also showed strong interaction
with organic acids and amino acids with the salinity treatment time
suggesting that organic acids and amino acids may be involved in
promoting salt-induced growth by regulating osmotic balance, ion
homeostasis, carbon and nitrogen balance under salt stress (Sharma et
al., 2018; Siddiqi & Husen, 2019). The results suggest that the
increased interaction between hormones and metabolites may be beneficial
for Pongamia to survive under extreme salinity stress (Sahoo et al.,
2014; Formentin et al., 2018).
The number of interactions between hormones and metabolites increased
with increasing treatment time in roots of 300 mM NaCl treated plants.
In contrast, the number interactions were decreased with the treatment
time in roots of 500 mM NaCl treated plants. The high correlation
between hormones and cell-wall carbohydrates and organic acids may
enhance the water permeability as well as pH regulation under salt tress
conditions (Marriboina et al., 2017; Marriboina & Attipalli, 2020a).
The increased association of hormones with organic acids may provide
immediate source of carbon energy and osmotic balance under salinity
stress conditions (Assaha et al., 2017; Böhm et al., 2018; Yang & Guo,
2018).