Changes in benzoxazinoid contents and the expression of the associated genes in rye (Secale cereale L.) due to brown rust and the inoculation procedure

Abstract

Benzoxazinoids (BXs) are secondary metabolites with diverse functions, but are primarily involved in protecting plants, mainly from the family Poaceae, against insects and fungal pathogens. Rye is a cereal crop that is highly resistant to biotic stresses. However, its susceptibility to brown rust caused by Puccinia recondita f. sp. secalis (Prs) is still a major problem affecting its commercial production. Additionally, the genetic and metabolic factors related to this disease remain poorly characterized. In this study, we investigated whether and to what extent the brown rust infection and the inoculation procedure affect the contents of specific BXs (HBOA, GDIBOA, DIBOA, GDIMBOA, DIMBOA, and MBOA) and the expression of genes related to BX (ScBx1-5, ScIgl, and Scglu). We revealed that treatments with water and a urediniospore suspension usually downregulate gene expression levels. Moreover, HBOA and DIBOA contents decreased, whereas the contents of the remaining metabolites increased. Specifically, the MBOA content increased more after the mock treatment than after the Prs treatment, whereas the increase in GDI-BOA and GDIMBOA levels was usually due to the Prs infection, especially at two of the most critical time-points, 17 and 24 h post-treatment. Therefore, GDIBOA and GDIMBOA are glucosides that are important components of rye defence responses to brown rust. Furthermore, along with MBOA, they protect rye against the stress associated with the inoculation procedure used in this study.

Role of sRNA molecules in the rye–leaf rust interaction

“…Plant materials, growth conditions, and treatment with the rust pathogen This study was conducted using the following three rye inbred lines: L318, which was bred by the Department of Plant Genetics, Breeding and Biotechnology, Warsaw University of Life Sciences (Warsaw, Poland), and D33 and D39, which were developed by Danko Plant Breeding, Ltd. (Poland). The inbred lines were selected according to the previously reported benzoxazinoid (BX) contents of eld-grown plants after a natural vernalization period [33] and differential seedling stage responses to an arti cial infection with a partially compatible Prs isolate [34].…”

The Roots of Rye (Secale cereale L.) Are Capable of Synthesizing Benzoxazinoids

“…Previously published protocols [ 11 , 52 ] with some modifications were used to quantify the following BXs: HBOA, GDIBOA, DIBOA, GDIMBOA, DIMBOA, and MBOA. Briefly, plant material (100 mg) was extracted with 70% methanol containing an internal standard (2 µg/mL indoxyl β-D-glucoside; IbG) under the conditions described previously.…”

“…The column effluent was redirected into the waste for the first 1.5 min of separation, to prevent contamination of the ion source with polar constituents of the sample matrix. The effluent was subsequently directed into a triple quadrupole mass spectrometer (Waters TQD, Waters, Milford, MA, USA) and analysed as described previously [ 11 , 14 , 52 ]. Data acquisition and processing were conducted using Waters MassLynx 4.1 SCN 919 software (Waters, Milford, MA, USA).…”

Changes in "natural antibiotic" metabolite composition during tetraploid wheat domestication

“…For example, the abundance of their glucoside derivatives is at the greatest level soon after germination, decreasing thereafter to lower levels 14 – 16 . Relative benzoxazinoids abundance has also been shown to vary among plant crops (e.g., maize and wheat 17 ), tissues (e.g., shoots and leaves 6 ), growth habitats (e.g., arid and humid 6 , 18 , 19 ), and even soil type (e.g., dry and wet 17 , 20 – 22 ). In addition, dramatic differences in benzoxazinoids content have been identified in microscale evolutionary contexts 22 .…”