title: Garlic (Allium sativum L.) fertility: transcriptome and proteome analyses provide insight into flower and pollen development.
abstract: Commercial cultivars of garlic, a popular condiment, are sterile, making genetic studies and breeding of this plant challenging. However, recent fertility restoration has enabled advanced physiological and genetic research and hybridization in this important crop. Morphophysiological studies, combined with transcriptome and proteome analyses and quantitative PCR validation, enabled the identification of genes and specific processes involved in gametogenesis in fertile and male-sterile garlic genotypes. Both genotypes exhibit normal meiosis at early stages of anther development, but in the male-sterile plants, tapetal hypertrophy after microspore release leads to pollen degeneration. Transcriptome analysis and global gene-expression profiling showed that >16,000 genes are differentially expressed in the fertile vs. male-sterile developing flowers. Proteome analysis and quantitative comparison of 2D-gel protein maps revealed 36 significantly different protein spots, 9 of which were present only in the male-sterile genotype. Bioinformatic and quantitative PCR validation of 10 candidate genes exhibited significant expression differences between male-sterile and fertile flowers. A comparison of morphophysiological and molecular traits of fertile and male-sterile garlic flowers suggests that respiratory restrictions and/or non-regulated programmed cell death of the tapetum can lead to energy deficiency and consequent pollen abortion. Potential molecular markers for male fertility and sterility in garlic are proposed.
authors.affiliation: Agricultural Research Organization, The Volcani Center, Institute of Plant Science Bet Dagan, Israel ; The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Hebrew University of Jerusalem Rehovot, Israel.
authors.forename: Einat
authors.initials: E
authors.lastname: Shemesh-Mayer
authors.affiliation: Agricultural Research Organization, The Volcani Center, Institute of Plant Science Bet Dagan, Israel ; The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Hebrew University of Jerusalem Rehovot, Israel.
authors.forename: Tomer
authors.initials: T
authors.lastname: Ben-Michael
authors.affiliation: The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Hebrew University of Jerusalem Rehovot, Israel.
authors.forename: Neta
authors.initials: N
authors.lastname: Rotem
authors.affiliation: The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Hebrew University of Jerusalem Rehovot, Israel.
authors.forename: Haim D
authors.initials: HD
authors.lastname: Rabinowitch
authors.affiliation: Agricultural Research Organization, The Volcani Center, Institute of Plant Science Bet Dagan, Israel.
authors.forename: Adi
authors.initials: A
authors.lastname: Doron-Faigenboim
authors.affiliation: Department of Environmental Stress Biology, Institute of Plant Genetics of the Polish Academy of Sciences Poznan, Poland.
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Kosmala
authors.affiliation: Department of Environmental Stress Biology, Institute of Plant Genetics of the Polish Academy of Sciences Poznan, Poland.
authors.forename: Dawid
authors.initials: D
authors.lastname: Perlikowski
authors.affiliation: Agricultural Research Organization, The Volcani Center, Institute of Plant Science Bet Dagan, Israel.
authors.forename: Amir
authors.initials: A
authors.lastname: Sherman
authors.affiliation: Agricultural Research Organization, The Volcani Center, Institute of Plant Science Bet Dagan, Israel.
authors.forename: Rina
authors.initials: R
authors.lastname: Kamenetsky
keywords: energy deficiency; gene expression; microsporogenesis; mitochondrial dysfunction; protein profiling; tapetum