Cytokinin-mediated source/sink modifications improve drought tolerance and increase grain yield in rice under water-stress.
Plant Biotechnol J
; 9(7): 747-58, 2011 Sep.
Article
em En
| MEDLINE
| ID: mdl-21284800
ABSTRACT
Drought is the major environmental factor limiting crop productivity worldwide. We hypothesized that it is possible to enhance drought tolerance by delaying stress-induced senescence through the stress-induced synthesis of cytokinins in crop-plants. We generated transgenic rice (Oryza sativa) plants expressing an isopentenyltransferase (IPT) gene driven by P(SARK) , a stress- and maturation-induced promoter. Plants were tested for drought tolerance at two yield-sensitive developmental stages pre- and post-anthesis. Under both treatments, the transgenic rice plants exhibited delayed response to stress with significantly higher grain yield (GY) when compared to wild-type plants. Gene expression analysis revealed a significant shift in expression of hormone-associated genes in the transgenic plants. During water-stress (WS), P(SARK)IPT plants displayed increased expression of brassinosteroid-related genes and repression of jasmonate-related genes. Changes in hormone homeostasis were associated with resource(s) mobilization during stress. The transgenic plants displayed differential expression of genes encoding enzymes associated with hormone synthesis and hormone-regulated pathways. These changes and associated hormonal crosstalk resulted in the modification of source/sink relationships and a stronger sink capacity of the P(SARK)IPT plants during WS. As a result, the transgenic plants had higher GY with improved quality (nutrients and starch content).
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oryza
/
Grão Comestível
/
Plantas Geneticamente Modificadas
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Alquil e Aril Transferases
/
Citocininas
/
Secas
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article