Yu, Xiaobo and Zhang, Xuecheng and Zhao, Peng and Peng, Xiongbo and Chen, Hong and Bleckmann, Andrea and Bazhenova, Anastasiia and Shi, Ce and Dresselhaus, Thomas and Sun, Meng-xiang (2021) Fertilized egg cells secrete endopeptidases to avoid polytubey. NATURE, 592 (7854). 433-+. ISSN 0028-0836, 1476-4687
Full text not available from this repository. (Request a copy)Abstract
Upon gamete fusion, animal egg cells secrete proteases from cortical granules to establish a fertilization envelope as a block to polyspermy(1-4). Fertilization in flowering plants is more complex and involves the delivery of two non-motile sperm cells by pollen tubes(5,6). Simultaneous penetration of ovules by multiple pollen tubes (polytubey) is usually avoided, thus indirectly preventing polyspermy(7,8). How plant egg cells regulate the rejection of extra tubes after successful fertilization is not known. Here we report that the aspartic endopeptidases ECS1 and ECS2 are secreted to the extracellular space from a cortical network located at the apical domain of the Arabidopsis egg cell. This reaction is triggered only after successful fertilization. ECS1 and ECS2 are exclusively expressed in the egg cell and transcripts are degraded immediately after gamete fusion. ECS1 and ESC2 specifically cleave the pollen tube attractor LURE1. As a consequence, polytubey is frequent in ecs1 ecs2 double mutants. Ectopic secretion of these endopeptidases from synergid cells led to a decrease in the levels of LURE1 and reduced the rate of pollen tube attraction. Together, these findings demonstrate that plant egg cells sense successful fertilization and elucidate a mechanism as to how a relatively fast post-fertilization block to polytubey is established by fertilization-induced degradation of attraction factors.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | IN-VITRO FERTILIZATION; ARABIDOPSIS; FUSION; ZYGOTE; BLOCK; ATTRACTANTS; POLYSPERMY; MECHANISMS; TRANSIENT; PROTEASE; |
| Subjects: | 500 Science > 580 Botanical sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Pflanzenwissenschaften |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 05 Sep 2022 08:50 |
| Last Modified: | 05 Sep 2022 08:50 |
| URI: | https://pred.uni-regensburg.de/id/eprint/46626 |
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