The Arabidopsis GPI-anchored protein COBL11 is necessary for regulating pollen tube integrity
Hongxia Li,
Yang Yang,
Hongkai Zhang,
Chengying Li,
Pingzhou Du,
Mengmeng Bi,
Tao Chen,
Dong Qian,
Yue Niu,
Haiyun Ren,
Lizhe An,
Yun Xiang
Affiliations
Hongxia Li
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Yang Yang
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Hongkai Zhang
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Chengying Li
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Pingzhou Du
Center for Biological Science and Technology, Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, Zhuhai-Macao Biotechnology Joint Laboratory, Advanced Institute of Natural Science, Beijing Normal University, Zhuhai 519087, China
Mengmeng Bi
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Tao Chen
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Dong Qian
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Yue Niu
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Haiyun Ren
Center for Biological Science and Technology, Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, Zhuhai-Macao Biotechnology Joint Laboratory, Advanced Institute of Natural Science, Beijing Normal University, Zhuhai 519087, China
Lizhe An
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
Yun Xiang
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China; Corresponding author
Summary: Pollen tube integrity is required for achieving double fertilization in angiosperms. The rapid alkalinization factor4/19-ANXUR1/2-Buddha’s paper seal 1/2 (RALF4/19-ANX1/2-BUPS1/2)-complex-mediated signaling pathway is critical to maintain pollen tube integrity, but the underlying mechanisms regulating the polar localization and distribution of these complex members at the pollen tube tip remain unclear. Here, we find that COBRA-like protein 11 (COBL11) loss-of-function mutants display a low pollen germination ratio, premature pollen tube burst, and seed abortion in Arabidopsis. COBL11 could interact with RALF4/19, ANX1/2, and BUPS1/2, and COBL11 functional deficiency could result in the disrupted distribution of RALF4 and ANX1, altered cell wall composition, and decreased levels of reactive oxygen species in pollen tubes. In conclusion, COBL11 is a regulator of pollen tube integrity during polar growth, which is conducted by a direct interaction that ensures the correct localization and polar distribution of RALF4 and ANX1 at the pollen tube tip.
