Part:BBa_K2286004

CKX3：Cytokinin-degrading Cytokinin Oxidase 3

This part includes a gene coding Cytokinin-degrading Cytokinin Oxidase（CKX）from Arabidopsis thaliana. This enzyme is the third in the CKX series gene of the Arabidopsis thaliana. The enzyme expressed by the CKX gene can affect plant development by degrading the cytokinin in the plant, resulting in slow plant growth and short plant. However, CKX overexpression can enhance the development of plant root system and get larger root through reducing the plant innate cytokinin status. In CKX gene family, CKX3 has a high expression level at the root. Therefore, it is suitable for root-specific expression to enhance the root system of plants.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

Characterization

To confirm the founction of CKX3,we used two different promoters PYK10(root-specific) and 35S to express the CKX3. From the below picture,we can see that the roots of tobacco carrying CKX3 are obviously larger than that of wild type,indicating that CKX3 can cause enhanced root Growth. What's more, the stems of tobacco carrying 35S promoter is smaller than that of wild type,indicating that CKX3 can affect the development of stems.

Fig. 1 Size of tobacco roots and stems.

References

1.Werner, T., et al., Root-specific reduction of cytokinin causes enhanced root growth, drought tolerance, and leaf mineral enrichment in Arabidopsis and tobacco. Plant Cell, 2010. 22(12): p. 3905-20.