RESUMEN
Characterized by a photocatalysis property, nanoanatase is closely related to the photosynthesis of spinach. It could not only improve light absorbance, transformation from light energy to electron energy, and active chemical energy, but also promote carbon dioxide (CO(2)) assimilation of spinach. However, the molecular mechanism of carbon reaction promoted by nanoanatase remains largely unclear. In this study, we report that the amounts of Rubisco activase (rca) mRNA in the nanoanatase-treated spinach were increased by about 51%, whereas bulk-TiO(2) treatment produced an increase of only 5%. Accordingly, the protein level of Rubisco activase from the nanoanatase-treated spinach was increased by 42% compared with the control; however, bulk-TiO(2) treatment resulted in a 5% improvement. Further analysis indicated that the activity of Rubisco activase in the nanoanatase-treated spinach was significantly higher than the control by up to 2.75 times, and bulk-TiO(2) treatment had no such significant effects. Together, one of the molecular mechanisms of carbon reaction promoted by nanoanatase is that the nanoanatase treatment results in the enhancement of rca mRNA expressions, protein levels, and activities of Rubisco activase, thereby leading to the improvement of Rubisco carboxylation and the high rate of photosynthetic carbon reaction.
Asunto(s)
Proteínas de Plantas/genética , Spinacia oleracea/enzimología , Titanio/farmacología , Western Blotting , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Proteínas de Plantas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Spinacia oleracea/genéticaRESUMEN
The mechanism of the fact that cerium improves the photosynthesis of plants under magnesium deficiency is poorly understood. The main aim of the study was to determine the role of cerium in the amelioration of magnesium deficiency effects in CO(2) assimilation of spinach. Spinach plants were cultivated in Hoagland's solution. They were subjected to magnesium deficiency and to cerium chloride administered in the magnesium-present Hoagland's media and magnesium-deficient Hoagland's media. The results showed that the chlorophyll synthesis and oxygen evolution was destroyed, and the activities of Rubisco carboxylasae and Rubisco activase and the expression of Rubisco large subunit (rbcL), Rubisco small subunit (rbcS), and Rubisco activase subunit (rca) were significantly inhibited, then plant growth was inhibited by magnesium deficiency. However, cerium promotes the chlorophyll synthesis, the activities of two key enzymes in CO(2) assimilation, and the expression of rbcL, rbcS, and rca, thus leading to the enhancement of spinach growth under magnesium-deficient conditions.
Asunto(s)
Carbono/metabolismo , Cerio/farmacología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Proteínas de Plantas/metabolismo , Ribulosa-Bifosfato Carboxilasa/metabolismo , Spinacia oleracea/efectos de los fármacos , Fotosíntesis/efectos de los fármacos , Proteínas de Plantas/clasificación , Proteínas de Plantas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ribulosa-Bifosfato Carboxilasa/clasificación , Ribulosa-Bifosfato Carboxilasa/genética , Spinacia oleracea/enzimología , Spinacia oleracea/crecimiento & desarrolloRESUMEN
Being a proven photocatalyst, nano-anatase is capable of undergoing electron transfer reactions under light. In previous studies, we had proven that nano-anatase improved photosynthesis and greatly promoted spinach growth. However, the molecular mechanisms of carbon reaction promoted by nano-anatase are still not clearly understood. In the present paper, reverse transcription polymerase chain reaction and Northern blotting were carried out, and the results showed that the expression of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) small subunit (rbcS) and Rubisco large subunit (rbcL) messenger RNA (mRNA) in the nano-anatase-treated spinach were obviously promoted, respectively, while the effects of bulk TiO2 were not so significant. Accordingly, the protein expression of Rubisco from the nano-anatase-treated spinach was increased by 40% compared with control. Further analysis indicated that the activity of Rubisco in the nano-anatase-treated spinach was significantly higher than the control, by up to 2.33 times, and bulk TiO2 treatment had no such significant effects. Together, one of the molecular mechanisms of carbon reaction promoted by nano-anatase is that the nano-anatase treatment results in the enhancement of Rubisco mRNA amounts, the protein levels, and activity of Rubisco, thereby leading to the improvement of Rubisco carboxylation and the high rate of photosynthetic carbon reaction.