Analysis of agonist-activity and antagonist-activity to cytokinin receptor

2:

• The method according to claim 1, wherein the transformed cell is a cell having a function of directly controlling the cell growth by intracellular signal transduction from the cytokinin receptor and the measurement of the existence or the quantity of the intracellular signal transduction is carried out using the quantity of the cell growth of the transformed cell as an indicator.

3:

• The method according to claim 1, wherein the transformed cell is a transformed cell generated by introducing DNA coding the cytokinin receptor into a host cell so improved as to have histidine kinase activity lower than the intrinsic histidine kinase activity of the host cell.

4:

• The method according to claim 1, wherein the transformed cell is a transformed cell generated by introducing DNA coding the cytokinin receptor into a host cell so improved as to have histidine kinase activity lower than the intrinsic histidine kinase activity of the host cell by deleting one or more of histidine kinase.

5:

• The method according to claim 1, wherein the transformed cell is a transformed cell generated by introducing DNA coding the cytokinin receptor into a host cell having no cytokinin receptor.

6:

• The method according to claim 1, wherein the transformed cell is yeast.

7:

• The method according to claim 1, wherein the transformed cell is budding yeast.

9:

• A method for analyzing antagonist-activity to a cytokinin receptor, which comprises
• (1) bringing an examinee substance and a substance having agonist-activity to the cytokinin receptor into contact with a transformed cell into which DNA coding the cytokinin receptor is introduced and
• (2) measuring the existence or the quantity of intracellular signal transduction from the cytokinin receptor expressed in the transformed cell.

10:

• The method according to claim 9, wherein the transformed cell is a cell having a function of directly controlling the cell growth by intracellular signal transduction from the cytokinin receptor and the measurement of the existence or the quantity of the intracellular signal transduction is carried out using the quantity of the cell growth of the transformed cell as an indicator.

11:

• The method according to claim 9, wherein the transformed cell is a transformed cell generated by introducing DNA coding the cytokinin receptor into a host cell so improved as to have histidine kinase activity lower than the intrinsic histidine kinase activity of the host cell.

12:

• The method according to claim 9, wherein the transformed cell is a transformed cell generated by introducing DNA coding the cytokinin receptor into a host cell so improved as to have histidine kinase activity lower than the intrinsic histidine kinase activity of the host cell by deleting one or more of histidine kinase.

13:

• The method according to claim 9, wherein the transformed cell is a transformed cell generated by introducing DNA coding the cytokinin receptor into a host cell having no cytokinin receptor.

14:

• The method according to claim 9, wherein the transformed cell is yeast.

15:

• The method according to claim 9, wherein the transformed cell is budding yeast.

18:

• DNA coding the cytokinin receptor of claim 17.

19:

• A transformed cell into which DNA of claim 18 is introduced.

20:

• A method for detecting agonist-activity to a cytokinin receptor, which comprises evaluating the agonist-activity of two or more different examinee substances to the cytokinin receptor based on the difference obtained by comparison of the existence or the quantity of the intracellular signal transduction in a section where the examinee substances are independently used and measured by the analysis method of claim 1.

21:

• The method according to claim 20, wherein at least one substance among the two or more different examinee substances is a substance having no agonist-activity to the cytokinin receptor.

22:

• A method for searching agonist-active substance to a cytokinin receptor, which comprises selecting a substance having agonist-activity to a cytokinin receptor based on the agonist-activity to a cytokinin receptor evaluated by the detecting method of claim 20.

23:

• A plant growth regulator comprising the substances selected by the searching method of claim 22 as an active ingredient.

24:

• A method for detecting antagonist-activity to a cytokinin receptor, which comprises evaluating the antagonist-activity of two or more different examinee substances to the cytokinin receptor based on the difference obtained by comparison of the existence or the quantity of the intracellular signal transduction in a section where the examinee substances are independently used and measured by the analysis method of claim 9.

25:

• The method according to claim 24, wherein at least one substance among the two or more different examinee substances is a substance having no antagonist-activity to the cytokinin receptor.

26:

• A method for searching antagonist-active substance to a cytokinin receptor, which comprises selecting a substance having antagonist-activity to a cytokinin receptor based on the antagonist-activity to a cytokinin receptor evaluated by the detecting method of claim 24.

27:

• A plant growth regulator comprising the substances selected by the searching method of claim 26 as an active ingredient.