Chemical intervention in plant sugar signalling increases yield and resilience

The pressing global issue of food insecurity due to population growth, diminishing land and variable climate can only be addressed in agriculture by improving both maximum crop yield potential and resilience. Genetic modification is one potential solution, but has yet to achieve worldwide acceptance, particularly for crops such as wheat. Trehalose-6-phosphate (T6P), a central sugar signal in plants, regulates sucrose use and allocation, underpinning crop growth and development. Here we show that application of a chemical intervention strategy directly modulates T6P levels in planta. Plant-permeable analogues of T6P were designed and constructed based on a ‘signalling-precursor’ concept for permeability, ready uptake and sunlight-triggered release of T6P in planta. We show that chemical intervention in a potent sugar signal increases grain yield, whereas application to vegetative tissue improves recovery and resurrection from drought. This technology offers a means to combine increases in yield with crop stress resilience. Given the generality of the T6P pathway in plants and other small-molecule signals in biology, these studies suggest that suitable synthetic exogenous small-molecule signal precursors can be used to directly enhance plant performance and perhaps other organism function

Diversification of an ancient theme: Hydroxynitrile glucosides

© 2008 Published by ElsevierMany plants produce cyanogenic glucosides as part of their chemical defense. They are α-hydroxynitrile glucosides, which release toxic hydrogen cyanide (HCN) upon cleavage by endogenous plant β-glucosidases. In addition to cyanogenic glucosides, several plant species produce β- and γ-hydroxynitrile glucosides. These do not release HCN upon hydrolysis by β-glucosidases and little is known about their biosynthesis and biological significance. We have isolated three β-hydroxynitrile glucosides, namely (2Z)-2-(β-d-glucopyranosyloxy)but-2-enenitrile and (2R,3R)- and (2R,3S)-2-methyl-3-(β-d-glucopyranosyloxy)butanenitrile, from leaves of Ribes uva-crispa. These compounds have not been identified previously. We show that in several species of the genera Ribes, Rhodiola and Lotus, these β-hydroxynitrile glucosides co-occur with the l-isoleucine-derived hydroxynitrile glucosides, lotaustralin (α-hydroxynitrile glucoside), rhodiocyanosides A (γ-hydroxynitrile glucoside) and D (β-hydroxynitrile glucoside) and in some cases with sarmentosin (a hydroxylated rhodiocyanoside A). Radiolabelling experiments demonstrated that the hydroxynitrile glucosides in R. uva-crispa and Hordeum vulgare are derived from l-isoleucine and l-leucine, respectively. Metabolite profiling of the natural variation in the content of cyanogenic glucosides and β- and γ-hydroxynitrile glucosides in wild accessions of Lotus japonicus in combination with genetic crosses and analyses of the metabolite profile of the F2 population provided evidence that a single recessive genetic trait is most likely responsible for the presence or absence of β- and γ-hydroxynitrile glucosides in L. japonicus. Our findings strongly support the notion that the β- and γ-hydroxynitrile glucosides are produced by diversification of the cyanogenic glucoside biosynthetic pathway at the level of the nitrile intermediate.Nanna Bjarnholt, Fred Rook, Mohammed Saddik Motawia, Claus Cornett, Charlotte Jørgensen, Carl Erik Olsen, Jerzy W. Jaroszewski, Søren Bak and Birger Lindberg Mølle

The β-glucosidases responsible for bio-activation of hydroxynitrile glucosides in <i>Lotus japonicus</i>

International audienc

The β-glucosidases responsible for bio-activation of hydroxynitrile glucosides in <i>Lotus japonicus</i>

International audienc

Mass spectrometry imaging (MSI) for plant metabolomics

Mass spectrometry imaging (MSI) is a developing technique to measure the spatiotemporal distribution of many biomolecules in tissues. Over the preceding decade MSI has been adopted by plant biologists and applied in a broad range of areas including: primary metabolism, natural products, plant defense, plant responses to abiotic and biotic stress, plant lipids, and the developing field of spatial metabolomics. This methods chapter covers preparation of plant tissues for matrix-assisted laser desorption ionization (MALDI)-MSI, including sample embedding and freezing, sectioning, mounting, and matrix deposition using both sublimation and spray deposition prior to MSI analysis