Data/hora: 05/06/2024 14:47:36

Biblioteca(s): | Embrapa Milho e Sorgo.
Data corrente: | 05/08/2005
Data da última atualização: | 17/10/2023
Autoria: | VASCONCELOS, M. J. V. de.
Título: | Determining the molecular basis of phosphorus efficiency in tropical maize and sorghum genotypes.
Ano de publicação: | 2004
Fonte/Imprenta: | 2004.
Páginas: | 183 f.
Idioma: | Inglês
Notas: | Tese (Doutorado) - Purdue University, West Lafayette.
Conteúdo: | Maize and sorghum are important crop species of the Brazilian savanna vegetation algo known as "cerrado". The soils in "cerrado" are mainly acidic which render phosphorus (Pi) unavailable to the plants. Pi is one of the essential nutrients required by plants and govems their growth, development and yield potentials. Coordinated induction of high affinity Pi transporters is one of the earlier molecular responses to Pi deficiency. In this study I used the genotypes of maize and sorghum exhibiting a wide spectrum of variability in their Pi use efficiency. To evaluate the role of Pi transporters in Pi utilization, I isolated and characterized high affinity Pi transporters (SbPT-1 and SbPT-2) from Sorghum bicolor. These transporters along with Pi transporters from Zea mays were transcriptionally regulated by Pi and exhibited spatio-temporal expression. Interestingly, the induction of SbPTs in stem of Pi efficient genotypes under nutrient deficiency suggest that not only acquisition but algo mobilization of Pi to different parts of the plants could have significant impact on yield potential. Furthermore, Pi transporters from maize and sorghum revealed differential expression in different parts of the root. In addition, microarray analysis of transcripts from phosphorus deficient roots of maize revealed a set of genes, such as those encoding a member of sulphate transporter family, A-1, glycerol-3-phosphate permease and BAT-3 a proline rich protein, which were responsive to Pi deficiency. A correlation was algo observed between the higher Pi use efficiency of the genotypes and some of the biochemical traits such as Pi content and anthocyanins accumulation in roots and shoots. There were striking differences in acid phosphatase activity between Pi efficient and inefficient genotypes. The study suggests that Pi transporters and some of the Pi responsive genes identified through microarray could serve as molecular determinants of Pi use efficiency in crop species grown in Pi-deprived acidic soils. These studies clearly showed that different molecular and biochemical traits contribute towards phosphorus efficiency in tropical maize and sorghum.
Thesagro: | Genética.
Categoria do assunto: | --
Registro original: | Embrapa Milho e Sorgo (CNPMS)
Exemplares: | CNPMS - (17825-1) - UPC - TS - PP - T.14/04 -  - T.14/04 - DIS