title: ABNORMAL POLLEN VACUOLATION1 (APV1) is required for male fertility by contributing to anther cuticle and pollen exine formation in maize.
abstract: Anther cuticle and pollen exine are the major protective barriers against various stresses. The proper functioning of genes expressed in the tapetum is vital for the development of pollen exine and anther cuticle. In this study, we report a tapetum-specific gene, Abnormal Pollen Vacuolation1 (APV1), in maize that affects anther cuticle and pollen exine formation. The apv1 mutant was completely male sterile. Its microspores were swollen, less vacuolated, with a flat and empty anther locule. In the mutant, the anther epidermal surface was smooth, shiny, and plate-shaped compared with the three-dimensional crowded ridges and randomly formed wax crystals on the epidermal surface of the wild-type. The wild-type mature pollen had elaborate exine patterning, whereas the apv1 pollen surface was smooth. Only a few unevenly distributed Ubisch bodies were formed on the apv1 mutant, leading to a more apparent inner surface. A significant reduction in the cutin monomers was observed in the mutant. APV1 encodes a member of the P450 subfamily, CYP703A2-Zm, which contains 530 amino acids. APV1 appeared to be widely expressed in the tapetum at the vacuolation stage, and its protein signal co-localized with the endoplasmic reticulum (ER) signal. RNA-Seq data revealed that most of the genes in the fatty acid metabolism pathway were differentially expressed in the apv1 mutant. Altogether, we suggest that APV1 functions in the fatty acid hydroxylation pathway which is involved in forming sporopollenin precursors and cutin monomers that are essential for the development of pollen exine and anther cuticle in maize.
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Yamuna
authors.initials: Y
authors.lastname: Somaratne
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Youhui
authors.initials: Y
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Huo
authors.affiliation: Heze Academy of Agricultural Sciences, Heze, Shandong, 274000, China.
authors.forename: Fengge
authors.initials: F
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Huabang
authors.initials: H
authors.lastname: Chen
mesh_terms: D005227:Fatty Acids / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D051479:Plant Infertility / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000378:metabolism*; D011058:Pollen / Q000235:genetics / Q000502:physiology*; D003313:Zea mays / Q000378:metabolism* / Q000502:physiology*
chemical_list: D005227:Fatty Acids; D010940:Plant Proteins
keywords: anther cuticle; maize; male sterility; microspore; pollen exine; tapetum