RESUMO
A systematic phytochemical study on the components in the seeds of Allium tuberosum was performed, leading to the isolation of 27 steroidal glycosides (SGs 1-27). The structures of SGs were identified mainly by nuclear magnetic resonance and mass spectrometries as well as the necessary chemical evidence. In the SGs, 1-10 and 22-26 are new steroidal saponin analogues. An in vitro bioassay indicates that 1, 2, 7, 8, 10, 13-15, 20, 23, and 26 display promotional roles in testosterone production of rat Leydig cells with the EC50 values of 1.0 to 4.5 µM, respectively.
Assuntos
Cebolinha-Francesa/química , Glicosídeos/química , Glicosídeos/farmacologia , Células Intersticiais do Testículo/efeitos dos fármacos , Esteroides/química , Esteroides/farmacologia , Testosterona/biossíntese , Animais , Glicosídeos/isolamento & purificação , Hidrólise , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/metabolismo , Espectroscopia de Ressonância Magnética , Masculino , Medicina Tradicional Chinesa , Cultura Primária de Células , Ratos Sprague-Dawley , Saponinas/química , Sementes/química , Espectrometria de Massas por Ionização por Electrospray , Esteroides/isolamento & purificaçãoRESUMO
The control of male fertility is of vital importance for crop breeding, hybrid generation, and the control of pollen release. Recent development in the analysis of Arabidopsis male sterile mutants has meant that there is a greater understanding of the gene regulatory networks controlling maternal development of the anther and the resultant sporophytes. With the advent of the genome sequence and tools to allow the analysis of gene function, this knowledge base is now extending into the monocot crop rice. This has shown high levels of similarity between the networks of pollen development in Arabidopsis and rice, which will serve as valuable tools to understand and manipulate this developmental pathway further in plants.
Assuntos
Arabidopsis/crescimento & desenvolvimento , Oryza/crescimento & desenvolvimento , Pólen/crescimento & desenvolvimento , Arabidopsis/citologia , Arabidopsis/genética , Flores/citologia , Flores/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Oryza/citologia , Oryza/genética , Pólen/citologia , Pólen/genética , Especificidade da EspécieRESUMO
As a complex wall system in flowering plants, the pollen outer wall mainly contains aliphatic sporopollenin; however, the mechanism for synthesizing these lipidic precursors during pollen development remains less well understood. Here, we report on the function of the rice tapetum-expressing TDR (Tapetum Degeneration Retardation) gene in aliphatic metabolism and its regulatory role during rice pollen development. The observations of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses suggested that pollen wall formation was significantly altered in the tdr mutant. The contents of aliphatic compositions of anther were greatly changed in the tdr mutant revealed by GC-MS (gas chromatography-mass spectrometry) testing, particularly less accumulated in fatty acids, primary alcohols, alkanes and alkenes, and an abnormal increase in secondary alcohols with carbon lengths from C29 to C35 in tdr. Microarray data revealed that a group of genes putatively involved in lipid transport and metabolism were significantly altered in the tdr mutant, indicating the critical role of TDR in the formation of the pollen wall. Also, a wide range of genes (236 in total-154 up-regulated and 82 down-regulated) exhibited statistically significant expressional differences between wild-type and tdr. In addition to its function in promoting tapetum PCD, TDR possibly plays crucial regulatory roles in several basic biological processes during rice pollen development.