title: Combined Cytological and Transcriptomic Analysis Reveals a Nitric Oxide Signaling Pathway Involved in Cold-Inhibited Camellia sinensis Pollen Tube Growth.
abstract: Nitric oxide (NO) as a signaling molecule plays crucial roles in many abiotic stresses in plant development processes, including pollen tube growth. Here, the signaling networks dominated by NO during cold stress that inhibited Camellia sinensis pollen tube growth are investigated in vitro. Cytological analysis show that cold-induced NO is involved in the inhibition of pollen tube growth along with disruption of the cytoplasmic Ca(2+) gradient, increase in ROS content, acidification of cytoplasmic pH and abnormalities in organelle ultrastructure and cell wall component distribution in the pollen tube tip. Furthermore, differentially expressed genes (DEGs)-related to signaling pathway, such as NO synthesis, cGMP, Ca(2+), ROS, pH, actin, cell wall, and MAPK cascade signal pathways, are identified and quantified using transcriptomic analyses and qRT-PCR, which indicate a potential molecular mechanism for the above cytological results. Taken together, these findings suggest that a complex signaling network dominated by NO, including Ca(2+), ROS, pH, RACs signaling and the crosstalk among them, is stimulated in the C. sinensis pollen tube in response to cold stress, which further causes secondary and tertiary alterations, such as ultrastructural abnormalities in organelles and cell wall construction, ultimately resulting in perturbed pollen tube extension.
authors.affiliation: College of Horticulture, Nanjing Agricultural University Nanjing, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Capital Normal University Beijing, China.
authors.forename: Xianyong
authors.initials: X
authors.lastname: Sheng
authors.affiliation: College of Horticulture, Nanjing Agricultural University Nanjing, China.
authors.forename: Zaifa
authors.initials: Z
authors.lastname: Shu
authors.affiliation: College of Horticulture, Nanjing Agricultural University Nanjing, China.
authors.forename: Dongqin
authors.initials: D
authors.lastname: Li
authors.affiliation: College of Horticulture, Nanjing Agricultural University Nanjing, China.
authors.forename: Junting
authors.initials: J
authors.lastname: Pan
authors.affiliation: College of Horticulture, Nanjing Agricultural University Nanjing, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Ye
authors.affiliation: College of Horticulture, Nanjing Agricultural University Nanjing, China.
authors.forename: Pinpin
authors.initials: P
authors.lastname: Chang
authors.affiliation: College of Horticulture, Nanjing Agricultural University Nanjing, China.
authors.forename: Xinghui
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Horticulture, Nanjing Agricultural University Nanjing, China.
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Wang
keywords: Camellia sinensis; cold stress; nitric oxide; pollen tube growth; signaling pathway