Metabolomics of Two Pecan Varieties Provides Insights into Scab Resistance

Abstract

UHPLC-MS-based non-targeted metabolomics was used to investigate the biochemical basis of pecan scab resistance. Two contrasting pecan varieties, Kanza (scab-resistant) and Pawnee (scab-susceptible), were profiled and the metabolomics data analyzed using multivariate statistics. Significant qualitative and quantitative metabolic differences were observed between the two varieties. Both varieties were found to have some unique metabolites. Metabolites that were only present or more abundant in Kanza relative to Pawnee could potentially contribute to the scab resistance in Kanza. Some of these metabolites were putatively identified as quercetin derivatives using tandem mass spectrometry. This suggests that quercetin derivatives could be important to pecan scab resistance.

Changes in Phenolic Metabolites and Biological Activities of Pumpkin Leaves (Cucurbita moschata Duchesne ex Poir.) During Blanching

“…Secondary fragments were also observed at m/z 299[M-H-308-15] due to cleavage of a methyl group from the aglycone moiety showing the presence of a methyl group in the aglycone. Peak 23 was tentatively identified as isorhamnetin-3-O-rutinoside and similar pattern of fragmentation was identified in the study as Lei et al ( 28 ). The MSE spectrum of peak 24 had a peak at m/z 315[M-H-191] from cleavage of the parent ion to produce the glycone and the aglycone moiety.…”

“…Peak 21 was thus tentatively identified as Isoorientin 2″-O-rhamnoside. In the MS/MS spectrum of peak 22, a base peak ion was observed at m/z 315.0538[M-H-308] − ; Lei et al ( 28 ) demostrated a similar fragmentation pattern. The loss of 308 indicated the compound was di-glycosylated having a hexose and a deoxyhexose with the ion at 315 being the aglycone ion.…”

Successful intergeneric transfer of a major apple scab resistance gene (Rvi6) from apple to pear and precise comparison of the downstream molecular mechanisms of this resistance in both species

“…The FLS gene leads to the biosynthesis of quercetin and kaempferol. These metabolites are activated after priming of tomato seeds with meJA in response to Fusarium , in rust infected leaves of black poplar, are involved in pecan scab resistance, and in Norway spruce rust resistance [83, 84, 85, 86]. Therefore, flavonoids, more specifically quercetin and kaempferol, could be involved in pear scab resistance.…”

Metabolic profiling revealed the organ‐specific distribution differences of tannins and flavonols in pecan

“…Phenolic metabolites in other organs of pecan trees also play critical roles in the defense of pathogens, injuries, and environment stresses. Such as metabolites in pecan leaves might play important roles in the resistant of scab (Lei et al, 2018).…”

“…By far, the phenolics in pecan were mostly studied in kernels (Gong & Pegg, 2017;Jia et al, 2018;Robbins et al, 2015;Robbins, Ma, Wells, Greenspan, & Pegg, 2014;de la Rosa et al, 2011), while studies in shell (Hilbig, Alves, et al, 2018), leaf (Gad et al, 2007;Ishak, Ahmed, Abd-Alla, & Saleh, 1980;Lei et al, 2018), and bark (Abdallah et al, 2011) were much less. There is no report of the rest of the organs.…”