Authors: Likai Wang Zhuqing Zhou Xuefang Song Jiwei Li Xiangyi Deng Fangzhu Mei
Publish Date: 2008/11/05
Volume: 234, Issue: 1-4, Pages: 87-96
Abstract
Transmission electron microscopy TEM and fluorescence microscopy studies revealed that the metaphloem sieve elements MSEs in the ventral vascular bundle of the caryopses of developing wheat Triticum aestivum L undergo a unique type of programmed cell death PCD Terminal deoxynucleotidyl transferasemediated dUTP nickend labeling TUNELpositive nuclei were observed at 3 and 4 days after flowering DAF Transmission electron microscopy studies of differentiating MSEs revealed increased vacuolation nuclear degeneration chromatin condensation and localization to the periphery of the nucleus and partly dilated perinuclear spaces all typical characteristics of PCD in plant cells In addition vacuoles were disrupted at the last stages of differentiation These results demonstrate that MSE differentiation is a unique type of PCD with highly selective autophagic processes in which PCD ceases just prior to death During this cessation of PCD vacuoles and the endoplasmic reticulum appear to be associated with selective organelle digestionThis paper has cost the time and energy of many people Our deepest gratitude goes first and foremost to the National Nature Science Foundation of China 30571101 for their financial support Moreover our sincere thanks go to Cao JianBo and Qin LiHong who helped us a lot by providing the transmission electron microscope technology We also owe our sincere thanks to our colleagues and family members who provided us with encouragement when we encountered difficulties in writing this paper Without their care and consideration this study would likely not have been completed
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