RESUMEN
Enhancing nitrogen use efficiency (NUE) in crop plants is an important breeding target to reduce excessive use of chemical fertilizers, with substantial benefits to farmers and the environment. In Arabidopsis (Arabidopsis thaliana), allocation of more NO3 (-) to shoots was associated with higher NUE; however, the commonality of this process across plant species have not been sufficiently studied. Two Brassica napus genotypes were identified with high and low NUE. We found that activities of V-ATPase and V-PPase, the two tonoplast proton-pumps, were significantly lower in roots of the high-NUE genotype (Xiangyou15) than in the low-NUE genotype (814); and consequently, less vacuolar NO3 (-) was retained in roots of Xiangyou15. Moreover, NO3 (-) concentration in xylem sap, [(15)N] shoot:root (S:R) and [NO3 (-)] S:R ratios were significantly higher in Xiangyou15. BnNRT1.5 expression was higher in roots of Xiangyou15 compared with 814, while BnNRT1.8 expression was lower. In both B. napus treated with proton pump inhibitors or Arabidopsis mutants impaired in proton pump activity, vacuolar sequestration capacity (VSC) of NO3 (-) in roots substantially decreased. Expression of NRT1.5 was up-regulated, but NRT1.8 was down-regulated, driving greater NO3 (-) long-distance transport from roots to shoots. NUE in Arabidopsis mutants impaired in proton pumps was also significantly higher than in the wild type col-0. Taken together, these data suggest that decrease in VSC of NO3 (-) in roots will enhance transport to shoot and essentially contribute to higher NUE by promoting NO3 (-) allocation to aerial parts, likely through coordinated regulation of NRT1.5 and NRT1.8.
Asunto(s)
Brassica napus/metabolismo , Nitratos/metabolismo , Nitrógeno/metabolismo , Raíces de Plantas/metabolismo , Vacuolas/metabolismo , Proteínas de Transporte de Anión/genética , Proteínas de Transporte de Anión/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Transporte Biológico/efectos de los fármacos , Transporte Biológico/genética , Brassica napus/clasificación , Brassica napus/genética , Diciclohexilcarbodiimida/farmacología , Regulación de la Expresión Génica de las Plantas , Genotipo , Pirofosfatasa Inorgánica/antagonistas & inhibidores , Pirofosfatasa Inorgánica/genética , Pirofosfatasa Inorgánica/metabolismo , Macrólidos/farmacología , Mutación , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/genética , Brotes de la Planta/genética , Brotes de la Planta/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Especificidad de la Especie , ATPasas de Translocación de Protón Vacuolares/antagonistas & inhibidores , ATPasas de Translocación de Protón Vacuolares/genética , ATPasas de Translocación de Protón Vacuolares/metabolismo , Vacuolas/genética , Xilema/genética , Xilema/metabolismoRESUMEN
OBJECTIVE: To investigate the clinical significance of atypical squamous cells of unknown significance (ASCUS) with abnormal DNA ploidy in the early diagnosis of cervical lesions. METHODS: Eight thousand four hundred and forty-eight patients were included in this study and all had DNA quantitative analysis and cervical liquid-based cytology. Among 1041 cases with DNA aneuploidy and/or abnormal cervical liquid-based cytology and additional cervical biopsy, histological review was performed in 247 ASCUS cases with abnormal DNA ploidy. RESULTS: (1) Among 8448 cases, 7877 were normal or benign, 426 were ASCUS, 45 were ASC-H, 55 were LSIL and 22 were HSIL by TBS diagnosis. The presence of 1-2 abnormal DNA ploidy cells was detected in 15.3% (65/426) of ASCUS, 11.1% (5/45) of ASC-H, 9.1% (5/55) of LSIL, and 0 (0/22) of HSIL. The presence of ≥ 3 abnormal DNA ploidy cells was detected in 39.0% (166/426) of ASCUS, 75.6% (34/45) of ASC-H, 76.4% (42/55) of LSIL, and 95.5% (21/22) of HSIL. (2) A total of 67 cases of CIN 2, CIN 3 or cancers were found in 247 patients with ASCUS by colposcopy biopsies, of which 13.9% (5/36) had 1-2 abnormal DNA ploidy cells, 45.5% (56/123) had ≥ 3 abnormal DNA ploidy cells and 6.8% (6/88) had normal DNA polidy. ASCUS with 1-2 abnormal DNA ploidy cells and with ≥ 3 abnormal DNA ploidy cells were compared. The difference was statistically significant (χ(2) = 11.79, P < 0.01). But the difference between ASCUS with 1-2 abnormal DNA ploidy cells and normal DNA ploidy had no statistical significance (P > 0.05). CONCLUSIONS: ASCUS with ≥ 3 abnormal DNA ploidy cells has higher risk for developing CIN 2, CIN 3 or invasive carcinoma. The application of DNA quantitative analysis and cervical liquid-based cytology test can help in guiding clinical follow-up and treatment options in patients with ASCUS.
Asunto(s)
Adenocarcinoma/diagnóstico , Aneuploidia , Carcinoma in Situ/diagnóstico , Carcinoma de Células Escamosas/diagnóstico , Displasia del Cuello del Útero/diagnóstico , Neoplasias del Cuello Uterino/diagnóstico , Adenocarcinoma/genética , Adenocarcinoma/patología , Adolescente , Adulto , Anciano , Carcinoma in Situ/genética , Carcinoma in Situ/patología , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Colposcopía , ADN de Neoplasias/genética , Femenino , Humanos , Persona de Mediana Edad , Displasia del Cuello del Útero/genética , Displasia del Cuello del Útero/patología , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología , Adulto JovenRESUMEN
Tetraploid sorghum (Sorghum bicolor L. Moench) line "sishentian" and Johnsongrass (Sorghum halepense L. Pers) were used to analyze genetic differences between Sorghum and Johnsongrass by SSR (simple sequence repeat) markers and cytogenetic methods. The SSR analyzed results indicated: (1) There were great genetic differences between sorghum and Johnsongrass, According to the different locus distribution, the chromosome linkage groups can be separated into two groups: High differences group and low differences group. (2) Cytogenetic analysis revealed that the parents and their hybrid are irregular tetraploid genetic populations; The chromosome configuration at MI were mainly bivalent and quadrivalents in sorghum, Johnsongrass and their hybrid; there were 17.00, 15.23, 15.83 bivalents and 0.95, 2.15, 1.60 quadrivalents in hybrid, sorghum and Johnsongrass respectively; The results of SSR and cytogenetic analysis demonstrated that the genome of Johnsongrass and Sorghum are homologous in a certain extent. The hybrid can not be steadily hereditary as double diploid.