• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.438-447
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• 2017

Flowering is one of the most important development traits related to the production of Brassica rapa crops. After planting, a sudden low temperature triggers premature flowering, which leads to a reduction in the yield and quality of harvested production. Therefore, understanding the mechanism of flowering control is important in the agricultural productivity for preventing Brassica rapa crops. Vernalization is generally known as the main factor of flowering in the Brassica plant. However, in the subspecies of Brassica rapa, some accession such as Yellow sarson and Komatsuna display the flowering phenotype without vernalization. Circadian genes, which diurnally regulate plant physiology, have a role for photoperiodic flowering but are related to the regulation of the vernalizarion mechanism. In this report, the 22 B. rapa accession were divided into two groups, vernalization and non-vernalization, and the sequenced circadian gene, BrPRR1s. Among them, the BrPRR1b gene was found to have deletion regions, which could classify the two groups. The PCR primer was designed to amplify a short band of 422bp in the vernalization type and a long band of 451bp in the non-vernalization type. This primer set was applied to distinguish the flowering types in the 43 B. rapa accession and 4 Brassica genus crop, Broccoli, cabbage, mustard, and rape. The PCR analysis results and flowering time information of each crop demonstrated that the primer set can be used as marker to discern the flowering type in Brassica crops. This marker system can be applied to the B. rapa breeding when selecting the flowering character of new progenies or introducing varieties at an early stage. In addition, these results displayed that the circadian clock genes can be a good strategy for the flowering control of B. rapa crops.

• Korean Journal of Plant Resources
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• v.22 no.3
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• pp.273-280
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• 2009

A cDNA clone encoding a MDR-like ABC transporter protein was isolated from Brassica rapa seedlings, through rapid amplification of cDNA ends (RACE). This gene (named as Brmdr 1; GenBank accession no.: DQ296184 ) had a total length of 4222 bp with an open reading frame of 3900 bp, and encoded a predicted polypeptide of 1300 amino acids with a molecular weight of 143.1 kDa. The BrMDR1 protein shared 71.0, 62.5, 60.0 and 58.2% identity with other MDR proteins isolated from Arabidopsis thaliana (AAN28720), Coptis japonica (CjMDR), Gossypium hirsutum (GhMDR) and Triticum aestivum (TaMDR) at amino acid level, respectively. Southern blot analysis showed that Brmdr1 was a low-copy gene. Expression pattern analysis revealed that Brmdr1 constitutively expressed in the root, stem petals and stamens, but with lower expression in leaves and open flowers. The domains analysis showed that BrMDR1 protein possessed two transmembrane domains (TMDs) and two nucleotide binding domains (NBDs) arranging in "TMD1-NBD1-TMD2-NBD2" direction, which is consistent with other MDR transporters. Within NBDs three characteristic motifs common to all ABC transporters, "Walker A", "Walker B" and C motif, were found. These results indicate that BrMDR1 is a MDR-like ABC transporter protein that may be involved in the transport and accumulation of secondary metabolites.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.329-335
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• 2021

Chinese cabbage fields have been damaged by cyst nematodes in highland of Gangwon province in Korea since the year 2011, and clover cyst nematode (CCN) is one of the most problematic cyst nematodes in the crop. To investigate the plant resources for breeding new Chinese cabbage cultivar, which is resistant to CCN, screening for resistance of fifty-seven Brassicaceae plant resources to CCN was conducted. Among the plant resources, fifty-four plant resources (Brassica rapa subsp. pekinensis, B. rapa, Brassica sp., B. juncea, B. carinata, B. rapa subsp. nipposinica, B. rapa subsp. narinosa, B. rapa var. perviridis, B. rapa var. perviridis, B. napus var. napobrassica, and Eruca sativa) were very susceptible to CCN and the number of females on roots was more than 300. Two plant resources (B. carinata and B. tournefortii) with more than 100 females on roots were susceptible to CCN. However, African mustard (B. tournefortii, Korean Genebank accession no. IT218058) was resistant to CCN because of the small number of females (4±1.8) on roots. This study showed that African mustard (IT218058) was valuable as a breeding material for Chinese cabbage, which is resistant to CCN.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.407-414
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• 2009

A cDNA clone encoding phytocystatin was isolated from Brassica rapa seedlings, through rapid amplification of cDNA ends (RACE). This gene (name as Brcpi1; GenBank accession no.: EF079953) had a total length of 881 bp with an open reading frame of 609 bp, and encoded predicted polypeptide of 203 amino acid (aa) residues including a putative N-terminal signal peptide. Other relevant regions found its sequence included the G and PW conserved aa motifs, and the consensus LARFAV sequence for phytocystatins and the reactive site QVVAG. The BrCPI1 protein shared 95, 94, 81, 80 and 78% identity with other CPI proterins isolated from Brassica oleracea (BoCPI-1), Arabidopsis thaliana (AtCY SB), Glycine max (GmCPI), Oryza sativa (OsCYS-2) and Zea may (ZmCPI) at amino acid level, respectively. Southern blot analysis showed that Brcpi1 was a low copy gene. Expression pattern analysis revealed that Brcpi1 was a tissue-specific expressing gene during reproductive growth and strongly expressed at mature seedling stages. Furthermore, overexpression of Brcpi1 in transgenic Arabidopsis was enhanced tolerance to salt and cold stresses. Meanwhile the juvenile seedling of Brcpi1 transgenic plants was not affected by various concentrations ABA in MS medium. Taken together, the results showed that Brcpi1 functioned as a cysteine protease inhibitor and it exhibited a protective agent against diverse types of abiotic stress, which induced this gene in a tissue- and stress-specific manner.