ThCOL2 Improves the Salt Stress Tolerance of Tamarix hispida

Abstract

The CONSTANS-LIKE (COL) transcription factor has been reported to play important roles in regulating plant flowering and the response to abiotic stress. To clone and screen COL genes with excellent salt tolerance from the woody halophyte Tamarix hispida, 8 ThCOL genes were identified in this study. The expression patterns of these genes under different abiotic stresses (high salt, osmotic, and heavy metal) and abscisic acid (ABA) treatment were detected using quantitative real-time PCR (qRT-PCR). The expression levels of 8 ThCOL genes changed significantly after exposure to one or more stresses, indicating that these genes were all stress-responsive genes and may be involved in the stress resistance response of T. hispida. In particular, the expression level of ThCOL2 changed significantly at most time points in the roots and leaves of T. hispida under salt stress and after ABA treatments, which may play an important role in the response process of salt stress through a mechanism dependent on the ABA pathway. The recombinant vectors pROKII–ThCOL2 and pFGC5941–ThCOL2 were constructed for the transient transformation of T. hispida, and the transient infection of T. hispida with the pROKII empty vector was used as the control to further verify whether the ThCOL2 gene was involved in the regulation of the salt tolerance response of T. hispida. Overexpression of the ThCOL2 gene in plants under 150 mM NaCl stress increased the ability of transgenic T. hispida cells to remove reactive oxygen species (ROS) by regulating the activity of protective enzymes and promoting a decrease in the accumulation of O2– and H2O2, thereby reducing cell damage or cell death and enhancing salt tolerance. The ThCOL2 gene may be a candidate gene associated with excellent salt tolerance. Furthermore, the expression levels of some genes related to the ABA pathway were analyzed using qRT-PCR. The results showed that the expressions of ThNCED1 and ThNCED4 were significantly higher, and the expressions of ThNCED3, ThZEP, and ThAAO3 were not significantly altered in OE compared with CON under normal conditions. But after 24 h of salt stress, the expressions of all five studied genes all were lower than the normal condition. In the future, the downstream genes directly regulated by the ThCOL2 transcription factor will be searched and identified to analyze the salt tolerance regulatory network of ThCOL2.

Involvement of Auxin-Mediated CqEXPA50 Contributes to Salt Tolerance in Quinoa (Chenopodium quinoa) by Interaction with Auxin Pathway Genes

“…There are similar reports that IAA significantly promotes the accumulation of POD enzymatic activities in potato ( Solanum tuberosum L.) and ground nutrients under salt stress [ 12 ]. The current results are consistent with previous reports, suggesting that increased antioxidant enzyme activity contributes to plant tolerance to stress [ 37 , 38 ]. However, with the addition of the auxin inhibitor NPA, the levels of photosynthetic pigments, ROS and enzyme activities in quinoa seedlings were not significantly different from those under salt stress, which further demonstrated that the regulation of antioxidant enzymatic and nonenzymatic systems during the maintenance of quinoa salt tolerance is dependent on IAA.…”

CRISPR/Cas9-Mediated Targeted Mutagenesis of GmUGT Enhanced Soybean Resistance Against Leaf-Chewing Insects Through Flavonoids Biosynthesis

“…For Arabidopsis transformation, the GmUGT gene was subcloned into pFGC5941 ( Lei et al, 2021 ) driven by the ATUGT72B1 promoter using the ClonExpress II One Step Cloning Kit (Vazyme, Nanjing, China); the clone, thus, prepared was introduced into the Arabidopsis atugt72b1 mutant with EHA105 by the floral dip method ( Clough and Bent, 1998 ).…”

Involvement of CONSTANS-like Proteins in Plant Flowering and Abiotic Stress Response

“…In addition, overexpression of Ghd2 in rice (Oryza sativa) significantly impairs drought resistance and plays a crucial role in drought-induced leaf senescence [154]. In the halophyte Tamarix hispida, ThCOL2 protein enhances the activity of protective enzymes, reduces ROS and MDA accumulation in plants, and mitigates cell damage to enhance salt tolerance in transgenic plants [155]. In maize (Zea mays), eight members of group I ZmCOL possess ABA-responsive cis-elements, and their expression levels are modulated by ABA, indicating their widespread involvement in ABA response [25].…”