RESUMEN
ADP-ribosylation factor1 (Arf1), a member of the small GTP-binding proteins, plays a pivotal role in protein trafficking to multiple organelles. In its GDP-bound form, Arf1 is recruited from the cytosol to organelle membranes, where it functions in vesicle-mediated protein trafficking. However, the mechanism of Arf1-GDP recruitment remains unknown. Here, we provide evidence that two Glo3p-type Arf GTPase-activating proteins (ArfGAPs), ArfGAP domain8 (AGD8) and AGD9, are involved in the recruitment of Arf1-GDP to the Golgi apparatus in Arabidopsis (Arabidopsis thaliana). RNA interference plants expressing low levels of AGD8 and AGD9 exhibited abnormal Golgi morphology, inhibition of protein trafficking, and arrest of plant growth and development. In RNA interference plants, Arf1 was poorly recruited to the Golgi apparatus. Conversely, high levels of AGD8 and AGD9 induced Arf1 accumulation at the Golgi and suppressed Golgi disruption and inhibition of vacuolar trafficking that was caused by overexpression of AGD7. Based on these results, we propose that the Glo3p-type ArfGAPs AGD8 and AGD9 recruit Arf1-GDP from the cytosol to the Golgi for Arf1-mediated protein trafficking, which is essential for plant development and growth.
Asunto(s)
Factor 1 de Ribosilacion-ADP/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Activadoras de GTPasa/metabolismo , Aparato de Golgi/metabolismo , Guanosina Difosfato/metabolismo , Factor 1 de Ribosilacion-ADP/genética , Secuencia de Aminoácidos , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/clasificación , Proteínas de Arabidopsis/genética , Western Blotting , Transferencia Resonante de Energía de Fluorescencia , Proteínas Activadoras de GTPasa/genética , Aparato de Golgi/ultraestructura , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Microscopía Confocal , Microscopía Electrónica de Transmisión , Datos de Secuencia Molecular , Mutación , Filogenia , Plantas Modificadas Genéticamente , Unión Proteica , Transporte de Proteínas/genética , Protoplastos/citología , Protoplastos/metabolismo , Interferencia de ARN , Homología de Secuencia de Aminoácido , Vacuolas/metabolismo , Vacuolas/ultraestructuraRESUMEN
Overexpression of Glu-1Bx7 via allele 1Bx7OE significantly contributes to high dough strength in some wheat varieties and is useful for improving wheat quality. However, the proportion of wheat varieties containing Bx7OE is quite low. In this study, four cultivars containing 1Bx7OE were selected, and among the selected varieties, Chisholm (1Ax2*, 1Bx7OE + 1By8*, and 1Dx5 + 1Dx10) was crossed with Keumkang, a wheat variety that contains 1Bx7 (1Ax2*, 1Bx7 + 1By8, and 1Dx5 + 1Dx10). SDS-PAGE and UPLC analyses showed that the expression of the high-molecular-weight glutenin subunit (HMW-GS) 1Bx7 was significantly higher in NILs (1Ax2*, 1Bx7OE + 1By8*, and 1Dx5 + 1Dx10) compared with that in Keumkang. Wheat quality was analyzed with near infrared reflectance spectroscopy by measuring the protein content and SDS-sedimentation of NILs. The protein content of NILs (12.94%) was 21.65% higher than that of Chisholm (10.63%) and 4.54% higher than that of Keumkang (12.37%). In addition, the SDS-sedimentation value of NILs (44.29 mL) was 14.97% and 16.44% higher than that of Keumkang (38.52 mL) and Chisholm (38.03 mL), respectively. This study predicts that the quality of domestic wheat can be improved by crossbreeding with 1Bx7OE-containing cultivars.