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The constitutive photomorphogenesis and dwarf (CPD) gene was initially isolated from an Arabidopsis thaliana (L.) Heynh. cpd mutant and encodes C‐3 oxidase as a key rate‐limiting enzyme in the brassinosteroids (BRs) biosynthesis pathway. For a better understanding of the molecular mechanism of CPD gene overexpression in potato (Solanum tuberosum L.) and CPD‐overexpressing potato plant tolerance to polyethylene glycol (PEG)‐induced osmotic stress, CPD gene was cloned by reverse transcription–polymerase chain reaction (RT‐PCR) from potato. The coding region was 1473 bp and encoded a deduced protein of 490 amino acids. The transgenic potato plants with CPD gene overexpression were obtained. Quantitative real‐time polymerase chain reaction (qRT‐PCR) analysis indicated that the CPD gene expressed in the roots, stems, and leaves of the transgenic and nontransgenic (NT) plants with particularly enhanced expression in the leaves. The proline content was 0.18‐ to 0.62‐fold higher and the malonaldedyde (MDA) content decreased by 45.1 to 87.4% in CPD‐overexpressing potato plants than in the NT plants under PEG‐induced osmotic stress conditions. The soluble sugar content, soluble protein content, and the superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), glutathione reductase (GR), and ascorbate peroxidase (APX) activities were all greater in the drought‐stressed transgenic plantlets at different sampling times than in the NT seedlings. These results indicated that CPD gene overexpression could ameliorate the effects of PEG‐induced osmotic stress. These results lay the foundation for further research on BR regulation in potato development and growth.

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BACKGROUND: Segmental distribution and expression of two heterodimeric amino acid transporter mRNAs during different ages were evaluated in pigs along the horizontal axis of the intestine.

Aphids, the largest group of sap-sucking pests, cause significant yield losses in agricultural crops worldwide every year. The massive use of pesticides to combat this pest causes severe damage to the environment, putting in risk the human health. In this study, transgenic potato plants expressing Galanthus nivalis agglutinin (GNA) gene were developed using CaMV 35S and ST-LS1 promoters generating six transgenic lines (35S1-35S3 and ST1-ST3 corresponding to the first and second promoter, respectively). Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the GNA gene was expressed in leaves, stems and roots of transgenic plants under the control of the CaMV 35S promoter, while it was only expressed in leaves and stems under the control of the ST-LS1 promoter. The levels of aphid mortality after 5 days of the inoculation in the assessed transgenic lines ranged from 20 to 53.3%. The range of the aphid population in transgenic plants 15 days after inoculation was between 17.0±1.43 (ST2) and 36.6±0.99 (35S3) aphids per plant, which corresponds to 24.9-53.5% of the aphid population in non-transformed plants. The results of our study suggest that GNA expressed in transgenic potato plants confers a potential tolerance to aphid attack, which appears to be an alternative against the use of pesticides in the future.