Overexpression of isochorismate synthase enhances salt tolerance in barley.

Isochorismate synthase (ICS) is a key enzyme for the synthesis of salicylic acid (SA) in plants. SA plays an important role in the response of plants to abiotic stress. In this study, transgenic barley was constructed to evaluate the function of ICS under salt stress. ICSOE lines showed obvious salt stress tolerance, this results from the increased outward Na+ flux and inward K+ flux in roots, thereby maintaining a lower cytosolic Na+/K+ ratio under salt stress. Overexprssion of ICS also improved Na+ sequestration in shoots under salt stress. In addition, ICSOE lines displayed less accumulation of reactive oxygen species and oxidative damage, accompanied by higher activity of antioxidant enzymes. The improved Na+/K+ ratio, Na+ sequestration, and antioxidative competence play an important role in the enhanced salt tolerance of ICSOE lines. These findings help to elucidate the abiotic stress resistance of the ICS pathway in barley.

Overexpression of isochorismate synthase enhances drought tolerance in barley.

Isochorismate synthase (ICS) is a key enzyme for the synthesis of salicylic acid (SA) in plants. SA mediates plant responses to both biotic and abiotic stresses. In previous studies, we found that overexpression of ICS (ICSOE) or suppression of ICS (ICSRNAi) affected the host response to Fusarium graminearum in barley. However, whether the barley ICS gene plays a role in adapting to abiotic stresses remains to be determined. In the present study, expression of the ICS gene was upregulated when treated with 20 % PEG6000, and ICSOE lines were more drought tolerant than wild type (WT) and ICSRNAi. In addition, the abscisic acid (ABA) levels in the ICSOE lines were higher than those in the WT and ICSRNAi lines under drought stress. High ABA levels significantly reduced Gs and E, which may impact water retention under drought stress. Under drought conditions, the activity of antioxidant enzymes was significantly higher in the ICSOE lines, correlating with a lower levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Enhanced antioxidant competence also contributed to drought tolerance in ICSOE lines. These findings help elucidate the abiotic stress resistance of the ICS pathway in barley.

Thermal degradation behaviors and reaction mechanism of carbon fibre-epoxy composite from hydrogen tank by TG-FTIR.

Thermal degradation behaviors and reaction mechanism of Carbon fibre-epoxy composite, obtained from Chinese widely applied hydrogen storage tank, were studied by thermogravimetry combined with Fourier transform infrared spectrometry at varying heating rates. The pyrolysis of carbon fibre-epoxy composite mainly occurs at 550-750 K. The average value of final residue is 72.42%. The calculated activation energies increase exponentially from 206.27 KJ/mol to 412.98 KJ/mol with the average value of 276.6 KJ/mol. The fourth reaction order model is responsible for the pyrolysis of carbon fibre-epoxy composite. The absorption spectra of the evolved gases provided the information that the main evolved products are H2O, CO2, CO (acid anhydride, ketone or aldehyde), ε- caprolactam, alcohols and phenol. Moreover, CO group > alcohols > phenol > ε- caprolactam > CO2 > H2O. Epoxy is the main pyrolysis crude material in carbon fibre-epoxy composite.