Sucrose feeding reverses shade-induced kernel losses in maize
BACKGROUND AND AIMS: Water limitations can inhibit photosynthesis and change gene expression in ways that diminish or prevent reproductive development in plants. Sucrose fed to the plants can reverse the effects. To test whether the reversal acts generally by replacing the losses from photosynthesis...
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| Published in: | Annals of botany Vol. 106; no. 3; pp. 395 - 403 |
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| Main Authors: | , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
England
Oxford University Press
01-09-2010
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | BACKGROUND AND AIMS: Water limitations can inhibit photosynthesis and change gene expression in ways that diminish or prevent reproductive development in plants. Sucrose fed to the plants can reverse the effects. To test whether the reversal acts generally by replacing the losses from photosynthesis, sucrose was fed to the stems of shaded maize plants (Zea mays) during reproductive development. METHODS: Shading was adjusted to mimic the inhibition of photosynthesis around the time of pollination in water-limited plants. Glucose and starch were imaged and quantified in the female florets. Sucrose was infused into the stems to vary the sugar flux to the ovaries. KEY RESULTS: Ovaries normally grew rapidly and contained large amounts of glucose and starch, with a glucose gradient favouring glucose movement into the developing ovary. Shade inhibited photosynthesis and diminished ovary and kernel size, weight, and glucose and starch contents compared with controls. The glucose gradient became small. Sucrose fed to the stem reversed these losses, and kernels were as large as the controls. CONCLUSIONS: Despite similar inhibition of photosynthesis, the depletion of ovary glucose and starch was not as severe in shade as during a comparable water deficit. Ovary abortion prevalent during water deficits did not occur in the shade. It is suggested that this difference may have been caused by more translocation in shade than during the water deficit, which prevented low sugar contents necessary to trigger an up-regulation of senescence genes known to be involved in abortion. Nevertheless, sucrose feeding reversed kernel size losses and it is concluded that feeding acted generally to replace diminished photosynthetic activity. |
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| Bibliography: | istex:244D9DA6F63AE7B8330762ACD71F682746E063C9 ArticleID:mcq132 Present address: National Agricultural Research Center for Kyushu Okinawa Region, 820 Makabe, Itoman, Okinawa, Japan. ark:/67375/HXZ-61VPCW2F-C ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 ObjectType-Article-2 ObjectType-Feature-1 Present address: Okinawa Prefectural Agricultural Research Center, 820 Makabe, Itoman, Okinawa, Japan. |
| ISSN: | 0305-7364 1095-8290 |
| DOI: | 10.1093/aob/mcq132 |