CsCAT3, a catalase gene fromCucumis sativus, confers resistance to a variety of stresses toEscherichia coli

Abstract

Catalase (CAT) is a key scavenging enzyme for the degradation of hydrogen peroxide (H 2 O 2 ) and plays an important role in the tolerance to diverse abiotic stresses in many different organisms. In this study, we characterized the function of a catalase gene (CsCAT3) previously isolated from Cucumis sativus in the defence against a variety of stresses. Protein alignment and phylogenetic analysis revealed that CsCAT3 was clustered in the dicot group and shared 41%-95% identity with other plant CATs. Expression analyses revealed that the expression of CsCAT3 was induced by diverse abiotic stresses such as heat, polyethylene glycol, cold and NaCl treatment, as well as by signalling molecules such as abscisic acid (ABA) and H 2 O 2 . An Escherichia coli heterologous expression system was constructed to characterize the function of CsCAT3 in vitro. Its overexpression in E. coli could increase the tolerance to heat, cold, salinity and osmotic conditions. These results indicate that CsCAT3 plays important roles in abiotic stress tolerance and that CsCAT3 confers tolerance in E. coli recombinants against abiotic stresses, which may be due to the increased activities of antioxidant enzymes that reduce the oxidative damage caused by stress conditions.

In Silico Identification and Expression Analysis of Nuclear Factor Y (Nf-Y) Transcription Factors in Cucumber

“…9930) was used in this study. Two-week-old cucumber seedlings were subjected to abiotic stress treatments including drought and salt as described in our previous study [32]. In brief, the seedlings were treated with 10% PEG-6000 (Sigma-Aldrich, Shanghai, China) and 200 mM NaCl to induce drought stress and salt stress, respectively.…”

“…The genomic DNA contamination was eliminated by RNase-free DNase I (TianGen, Beijing, China), and the first-strand cDNA was obtained using the M-MLV reverse transcriptase (Invitrogen, Carlsbad, CA, USA). The qRT-PCR was performed using the TB Green Premix Ex TaqII Kit (TaKaRa Biotechnology, Dalian, China) and the amplification program was set as previously described [32]. Three biological replicates were performed to test the expression of all the selected genes.…”

“…Cucumber (Cucumis sativus L.) is one of the worldwide popular vegetable crops, and belongs to the genus Cucumis in Cucurbitaceae, which is prone to be threatened by various abiotic stresses [32]. Therefore, identification and characterization of genes related to stress resistance in cucumber would be of great significance to the improvement of resistance, yield, and quality of cucumber plants in future cucumber planting.…”

Characterization and expression analysis of growth regulating factor (GRF) family genes in cucumber

“…Chinese long No. 9930) were subjected to salt and drought stress conditions, which were described in our previous study [36]. The leaf tissues were collected at 0, 3, 6, and 12 h, frozen immediately in liquid nitrogen and stored at -80°C until RNA isolation.…”

“…The first-strand cDNA was synthesized using the SuperscriptIII RNase H-Reverse Transcriptase kit (Invitrogen, USA) following the manufacturer's instructions. qRT-PCR was performed in triplicate using the SYBR Green Master Mix (Tiangen, China) as described previously [36]. The cucumber actin gene (CsAct3) was used as an internal control and the relative expression level was calculated using the 2 -ΔΔCT method [37], and the expression of control plants (without treatment, 0 h) was normalized to 1.…”