Table 1

List of over-lapping PCR primers"

Table 2

Standard reaction system for producing amiRNA precursor"

Table 3

Gene-specific primers sequences for qRT-PCR analysis of potato"

Fig. 1

PCR products of recombinant plasmid amiRNAs of a, b, and c M: DL2000 marker; 1: fragment a; 2: fragment b; 3: fragment c."

Fig. 2

Test of recombinant plasmid amiRNAs of fragment d a: PCR products of fragment d; b: Kpn I/Sac I double enzyme digestion products of fragment d; M: DL2000 marker; 1: fragment d."

Fig. 3

Sequencing results of recombinant plasmid amiRNA of fragment d The blue section represents the mature sequence of miR319a on the original pRS300 vector and its reverse sequence, the red part represents the mature sequence of potato miR167 and its reverse sequence after PCR amplification."

Fig. 4

Verification of transgenic plants by PCR assay of nptII gene M: DL2000 marker (TaKaRa); 1: plasmid pBI121 as a positive control; 2: untransformed potato plant as a negative control; 3-7: transgenic potato plants."

Fig. 5

StCPD gene expression level in the transgenic plants tested by qRT-PCR NT: non-transgenic plant; Ci1-Ci5: five different transgenic plant lines."

Fig. 6

Tissue-specific expression level of StCPD gene in transgenic and NT potato plants tested by qRT-PCR NT is untransformed potato plants; Ci1, Ci3, and Ci4 are three different transgenic plant lines. Significant differences among means over the different tissues were determined according to Duncan’s test at P<0.05. The line bars are standard errors (n = 9, i.e., three replicates × three runs of the experiment)."

Table 4

Phenotypic analysis of StCPD amiRNA expressed transgenic potato plants"

Fig. 7

Effects of drought stress treatments on relative expression levels of the StCPD gene in non-transgenic (NT, A) and transgenic (B) potato plants Significant differences among means over the period (d) of drought-stress treatments were determined according to Duncan’s test at P<0.05. The line bars are standard errors (n = 9, i.e., three replicates × three runs of the experiment)."

Fig. 8

MDA contents in transgenic and non-transgenic (NT) potato plants The NT and transgenic plant lines were divided into two groups, a control group under normal conditions and another group soaked in 20% PEG-8000 for 0-6 d after growing in MS medium for 4 weeks. Significant differences among means over the period (d) of drought-stress treatments were determined according to Duncan’s test at P<0.05. The line bars are standard errors (n = 9, i.e., 3 replicates × 3 runs of the experiment)."

Fig. 9

Proline contents in transgenic and non-transgenic (NT) potato plantsThe NT and transgenic plant lines were divided into two groups, a control group under normal conditions and another group soaked in 20% PEG-8000 for 0-6 d after growing in MS medium for 4 weeks. Significant differences among means over the period (d) of drought-stress treatments were determined according to Duncan’s test at P<0.05. The line bars are standard errors (n = 9, i.e., 3 replicates × 3 runs of the experiment)."

Fig. 10

Phenotypic difference between the transgenic test-tube plants under drought stress and control treatmentCi1, Ci3: transgenic plants of control; Ci1’, Ci3’: transgenic plants under drought stress. The scale bar is 1 cm."

Table 5

Effects of drought stress on the phenotype of StCPD interference-expressing potato plants"