The Impact of Chronic High Temperatures on Anther and Pollen Development in Cultivated Oryza Species

Rice is the leading staple for half the world’s population. Climate change, expanding populations and loss of agricultural land are projected to reduce rice yields by upwards of 30%. Significantly, rice yields decline by 10% for every 1°C increase in temperature. Temperatures ≥ 32°C can cause failur...

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Bibliographic Details
Main Author: Bagha, Shaheen
Other Authors: Sage, Tammy
Language:en_ca
Published: 2014
Subjects:
Online Access:http://hdl.handle.net/1807/44094
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spelling ndltd-TORONTO-oai-tspace.library.utoronto.ca-1807-440942014-03-21T04:01:51ZThe Impact of Chronic High Temperatures on Anther and Pollen Development in Cultivated Oryza SpeciesBagha, ShaheenHigh temperatureRice0359Rice is the leading staple for half the world’s population. Climate change, expanding populations and loss of agricultural land are projected to reduce rice yields by upwards of 30%. Significantly, rice yields decline by 10% for every 1°C increase in temperature. Temperatures ≥ 32°C can cause failure in male reproductive development and eliminate yields in some cultivars. This dissertation determined the developmental features and mechanisms associated with failure in male reproduction at temperatures of 32 °C and 36 °C in temperature tolerant and sensitive cultivars of O. sativa and O. glaberrima. Temperatures of 32 °C impaired anther dehiscence in the temperature sensitive cultivar of O. sativa by preventing septum cell wall degradation, which is essential for pollen dispersal. Temperatures of 36 °C induced abortion in pollen development either during meiosis primarily in O. sativa or at the uninucleate stage in O. glaberrima. Abortion during meiosis was associated with autophagic programmed cell death, whereas failure at the uninucleate stage of pollen development was associated with features of necrosis such as cytoplasmic shrinkage and cell wall collapse. Increased hydrogen peroxide production was detected in aborting meiocytes and uninucleate microspores at 36 °C, indicating that this reactive oxygen species may contribute to the failure of male reproductive development in rice during high temperature stress. Identification of the timing of failure in male reproductive development, and the cellular features associated with these processes in rice, form the basis for the identification of molecular mechanisms that control yield responses to high temperature stress.Sage, Tammy2014-032014-03-20T17:05:44ZNO_RESTRICTION2014-03-20T17:05:44Z2014-03-20Thesishttp://hdl.handle.net/1807/44094en_ca
collection NDLTD
language en_ca
sources NDLTD
topic High temperature
Rice
0359
spellingShingle High temperature
Rice
0359
Bagha, Shaheen
The Impact of Chronic High Temperatures on Anther and Pollen Development in Cultivated Oryza Species
description Rice is the leading staple for half the world’s population. Climate change, expanding populations and loss of agricultural land are projected to reduce rice yields by upwards of 30%. Significantly, rice yields decline by 10% for every 1°C increase in temperature. Temperatures ≥ 32°C can cause failure in male reproductive development and eliminate yields in some cultivars. This dissertation determined the developmental features and mechanisms associated with failure in male reproduction at temperatures of 32 °C and 36 °C in temperature tolerant and sensitive cultivars of O. sativa and O. glaberrima. Temperatures of 32 °C impaired anther dehiscence in the temperature sensitive cultivar of O. sativa by preventing septum cell wall degradation, which is essential for pollen dispersal. Temperatures of 36 °C induced abortion in pollen development either during meiosis primarily in O. sativa or at the uninucleate stage in O. glaberrima. Abortion during meiosis was associated with autophagic programmed cell death, whereas failure at the uninucleate stage of pollen development was associated with features of necrosis such as cytoplasmic shrinkage and cell wall collapse. Increased hydrogen peroxide production was detected in aborting meiocytes and uninucleate microspores at 36 °C, indicating that this reactive oxygen species may contribute to the failure of male reproductive development in rice during high temperature stress. Identification of the timing of failure in male reproductive development, and the cellular features associated with these processes in rice, form the basis for the identification of molecular mechanisms that control yield responses to high temperature stress.
author2 Sage, Tammy
author_facet Sage, Tammy
Bagha, Shaheen
author Bagha, Shaheen
author_sort Bagha, Shaheen
title The Impact of Chronic High Temperatures on Anther and Pollen Development in Cultivated Oryza Species
title_short The Impact of Chronic High Temperatures on Anther and Pollen Development in Cultivated Oryza Species
title_full The Impact of Chronic High Temperatures on Anther and Pollen Development in Cultivated Oryza Species
title_fullStr The Impact of Chronic High Temperatures on Anther and Pollen Development in Cultivated Oryza Species
title_full_unstemmed The Impact of Chronic High Temperatures on Anther and Pollen Development in Cultivated Oryza Species
title_sort impact of chronic high temperatures on anther and pollen development in cultivated oryza species
publishDate 2014
url http://hdl.handle.net/1807/44094
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