Kitazawa, Daisuke, Hatakeda, Yasuko, Fujii, Nobuharu, Miyazawa, Yutaka, Suge, Hiroshi, Takahashi, Hideyuki, Kamada, Motoshi, Hoshino, Atsushi, Iida, Shigeru, and Fukaki, Hidehiro
An agravitropic mutant of morning glory (Pharbitis nil.), weeping, has defect in shoot gravitropism. The previous results showed that weeping also showed defect in proper endodermis development and in shoot circumnutation, and such defect in circumnutation was also observed in similar endodermis-less Arabidopsis mutant, scarecrow (scr). In search of the mutated gene of weeping, cDNAs for SCR homolog from morning glory (PnSCR) were cloned from both wild type and weeping, respectively, and analyzed. An amino acid insertion was found in PnSCR from weeping. To investigate whether this insertion inactivates the PnSCR functions, complementation test was performed by introducing wild and weeping type PnSCR to the different Arabidopsis scr mutants respectively. As a result, endodermis-less and shoot agravitropic phenotypes were rescued by wild type introducing PnSCR, whereas introduction of weeping type PnSCR did not rescue them. Moreover, shoot circumnutation was also restored in scr mutant to which wild type PnSCR was transformed, but transformed weeping type PnSCR did not restore shoot circumnutation. These results strongly suggest that defects in gravitropism, proper endodermis development, and circumnutation observed in weeping are attributable to the loss of function of PnSCR. Possibility for usage of weeping morning glory as a new model plant in space biology is discussed., 資料番号: AA0048095069