Impacts of T-Phylloplanin Gene Knockdown and of Helianthus and Datura Phylloplanins on Peronospora tabacina Spore Germination and Disease Potential

Abstract

T-phylloplanin proteins secreted to aerial surfaces of tobacco (Nicotiana tabacum) by short procumbent trichomes inhibit spore germination and blue mold disease caused by the oomycete pathogen Peronospora tabacina. Many other plants were found to contain water-washed leaf surface proteins (phylloplanins), but the functions and properties of these are not known. Here we extend earlier evidence for the antifungal activity of T-phylloplanins using a reverse genetics approach. RNA interference of the T-phylloplanin gene in tobacco 'T.I. 1068' resulted in loss of T-phylloplanin mRNA and protein, loss of in vitro spore germination inhibition activity, and leaf infection inhibition activity of leaf water washes from RNA interference plants, and young knockdown plants were susceptible to disease. The glycoprotein character, adaxial-leaf-surface enrichment of, and renewability of T-phylloplanins are also described. We also report that leaf water washes of sunflower (Helianthus annuus) and jimson weed (Datura metel), but not soybean (Glycine max), like that of tobacco, possess ProteinaseK-and boiling-sensitive P. tabacina spore germination and tobacco leaf infection inhibition activities. Results establish that T-phylloplaninins of tobacco are active in P. tabacina inhibition, and indicate that leaf surface proteins of certain non-Nicotiana species that are not susceptible to P. tabacina disease can inhibit germination of spores of this oomycete pathogen and inhibit tobacco leaf infection by this pathogen.

Use of Several Natural Products from Selected Nicotiana Species to Prevent Black Shank Disease in Tobacco

“…These chemicals have previously shown antifungal, insecticidal, and antibacterial properties (14,19,20,22,29,37,38) but have not been studied for black shank prevention. There are preliminary indications that cis-abienol and phylloplanin have a potential against black shank in laboratory conditions (22).…”

“…A tobacco phylloplanin (T-phylloplanin) was isolated from TI 1068, and characterized as a protein produced and secreted by tobacco short glandular trichomes. T-phylloplanin was found to be active against blue mold spores (19)(20)(21), and also to delay black shank infection of the roots of dark tobacco in a tube and a soil drench assay (22). cis-Abienol is a valuable natural product synthesized by glandular trichomes and secreted in the leaf gum in some tobaccos (23,24).…”

Harnessing plant trichome biochemistry for the production of useful compounds

“…In addition to secreting small molecules (for example acyl sugars), recent evidence indicates that trichomes of tobacco actively secrete water-soluble low-molecularweight glycoproteins, known as phylloplanins, to the leaf surface (Kroumova et al, 2007;Shepherd et al, 2005). These studies demonstrated that phylloplanins can inhibit spore germination and the onset of blue-mold disease caused by the oomycete pathogen Peronospora tabacina; tobacco plants with reduced levels of phylloplanin mRNA and protein are more susceptible to pathogen infection.…”

“…These small proteins deposited at the leaf surface thus represent an early line of defense against microbial invaders. Pathogen spore germination assays using water-soluble leaf proteins from other plants showed that leaf surface-localized antimicrobial proteins are not restricted to tobacco (Kroumova et al, 2007). However, it is not yet known whether the leaf surface proteins on other plants are homologous to the tobacco phylloplanins.…”

Synthesis, Characterization and In Vitro Antitumor Activity of Glucosyl Ester Derivatives Containing Amino Acid Linker

“…Development of anti‐tumor drugs are the duty of medical workers. In the new drug research procedure, finding an active leading compound is the foundation of all the research work …”