RESUMO
Sorbitol is the primary photosynthate and translocated carbohydrate in fruit trees of the Rosaceae family. NAD(+)-dependent sorbitol dehydrogenase (NAD-SDH, EC 1.1.1.14), which mainly catalyzes the oxidation of sorbitol to fructose, plays a key role in regulating sink strength in apple. In this study, we found that apple NAD-SDH was ubiquitously distributed in epidermis, parenchyma, and vascular bundle in developing cotyledon. NAD-SDH was localized in the cytosol, the membranes of endoplasmic reticulum and vesicles, and the vacuolar lumen in the cotyledon at the middle stage of seed development. In contrast, NAD-SDH was mainly distributed in the protein storage vacuoles in cotyledon at the late stage of seed development. Sequence analysis revealed there is a putative signal peptide (SP), also being predicated to be a transmembrane domain, in the middle of proteins of apple NAD-SDH isoforms. To investigate whether the putative internal SP functions in the vacuolar targeting of NAD-SDH, we analyzed the localization of the SP-deletion mutants of MdSDH5 and MdSDH6 (two NAD-SDH isoforms in apple) by the transient expression system in Arabidopsis protoplasts. MdSDH5 and MdSDH6 were not localized in the vacuoles after their SPs were deleted, suggesting the internal SP functions in the vacuolar targeting of apple NAD-SDH.
Assuntos
L-Iditol 2-Desidrogenase/metabolismo , Malus/enzimologia , Sinais Direcionadores de Proteínas , Sementes/enzimologia , Vacúolos/enzimologia , Sequência de Aminoácidos , Cotilédone/enzimologia , Cotilédone/genética , Cotilédone/ultraestrutura , Imuno-Histoquímica , L-Iditol 2-Desidrogenase/química , L-Iditol 2-Desidrogenase/genética , Malus/genética , Malus/ultraestrutura , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , NAD/metabolismo , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/ultraestrutura , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transporte Proteico , Proteínas Recombinantes de Fusão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sementes/genética , Sementes/ultraestrutura , Alinhamento de Sequência , Deleção de Sequência , Sorbitol/metabolismoRESUMO
OBJECTIVE: To improve clinicians' ability of diagnosing testicular torsion. METHODS: We reviewed the data of a case of testicular torsion that resulted in necrosis because of delayed presentation and repeated misdiagnosis, and analyzed its anatomic features, clinical manifestations, ultrasound results, the causes of misdiagnosis and relevant literature. RESULTS: The patient presented 5 hours after the onset of symptoms, complaining of severe paroxysmal pain in the lower left abdomen, accompanied with nausea and vomiting, and was twice misdiagnosed as having enterospasm or ureteral calculus at two different hospitals. Fifteen hours later, surgical exploration revealed an about 900-degree testicular torsion in the spermatic cord, which necessitated orchiectomy for non viability of the testis. Postoperative pathological examination confirmed testicular necrosis and diffused hemorrhage in the testis and epididymis. CONCLUSION: Timely presentation, correct diagnosis and proper treatment are keys to saving the affected testis. Color Doppler ultrasound is an ideal option for the definite diagnosis of acute scrotal diseases, and it offers a valuable guidance for related surgery as well.
