Biology subjects

Craze, M.

Publications and source records attributed to Craze, M..

4 recordsLinked to original sources

bioRxiv2022

OsPSTOL but not TaPSTOL can play a role in nutrient use efficiency and works through conserved pathways in both wheat and rice

There is a large demand to reduce inputs for current crop production, particularly phosphate and nitrogen inputs which are the two most frequently added supplements to agricultural production. Gene characterization is often limited to the native species from which it was identified, but may offer benefits to other species. To understand if OsPSTOL, a gene identified from rice which improves tolerance to low P growth conditions, might improve performance and provide the same benefit in wheat, OsPSTOL was transformed into wheat and expressed from a constitutive promoter. The ability of OsPSTOL to improve nutrient acquisition under low phosphate or low nitrogen was evaluated. Here we show that OsPSTOL works through a conserved pathway in wheat and rice to improve yields under both low phosphate and low nitrogen. This increase is yield is mainly driven by improved uptake from the soil driving increased biomass and ultimately increased seed number, but does not change the concentration of N in the straw or grain. Overexpression of OsPSTOL in wheat modifies N regulated genes to aid in this uptake whereas the putative homolog TaPSTOL does not suggesting that expression of OsPSTOL in wheat can help to improve yields under low input agriculture.

plant biology↗

bioRxiv2022

Wheat cells show positional responses to invasive Zymoseptoria tritici

The stomatal complex of grasses consists of two guard cells and two adjacent subsidiary cells that cooperate during stomatal closure. Zymoseptoria tritici, the main causal agent of Septoria tritici blotch in wheat, enters the host via stomata. Here we test the hypothesis that the stomatal complex shows focused sub-cellular responses to invading Z. tritici hyphae. We have combined live-cell transmission light microscopy, immunofluorescence and CRS microscopy to identify cell wall modifications triggered by hyphal invasion. Furthermore, we have used confocal fluorescence microscopy and automated quantitative image analysis to assess whether host cells respond to hyphae through spatial redistribution of organelles. We find that subsidiary cells construct papillae that are accurately aligned with hyphal position even when hyphae are occluded by guard cells. These are distinct from those induced by powdery mildew, with callose restricted to a crust that surrounds content with a high-amplitude Raman signal in the CH-band. Peroxisome populations in subsidiary cells show distributions with modes weakly correlated with hyphal position but do not differ significantly between compatible and incompatible interactions. Our data suggest local changes to cell wall architecture and focal accumulation of organelles in subsidiary cells could play roles in crop defence during host leaf penetration by Z. tritici. Molecular strategies to amplify these responses may provide novel routes for crop protection.

plant biology↗

bioRxiv2021

Over-expression of the brassinosteroid gene TaDWF4 increases wheat productivity under low and sufficient nitrogen through enhanced carbon assimilation

There is a strong pressure to reduce nitrogen (N) fertiliser inputs while maintaining or increasing current cereal crop yields. Brassinosteroids, (BR), are a group of phytohormones essential for plant growth and development, that have been demonstrated to regulate several agronomic traits. DWF4 encodes a cytochrome P450 that catalyses a rate-limiting step in BR synthesis. We show that overexpression of the dominant shoot expressed homoeologue TaDWF4-B in wheat can increase plant productivity by up to 105% under a range of N levels on marginal soils, resulting in increased N use efficiency (NUE). We show that a two to four-fold increase in TaDWF4 transcript levels enhances the responsiveness of genes regulated by N. The productivity increases seen were primarily due to the maintenance of photosystem II operating efficiency and carbon assimilation in plants when grown under limiting N conditions and not an overall increase in photosynthesis capacity. The increased biomass production and yield per plant in TaDWF4 OE lines could be linked to modified carbon partitioning and changes in expression pattern of the growth regulator Target Of Rapamycin, offering a route towards breeding for sustained yield and lower N inputs.

plant biology↗

bioRxiv2018

A fungal ribonuclease-like effector protein inhibits plant host ribosomal RNA degradation

The biotrophic fungal pathogen Blumeria graminis causes the powdery mildew disease of cereals and grasses. Proteins with a predicted ribonuclease (RNase)-like fold (termed RALPHs) comprise the largest set of secreted effector candidates within the B. graminis f. sp. hordei genome. Their exceptional abundance suggests they play crucial functions during pathogenesis. We show that transgenic expression of RALPH CSEP0064/BEC1054 increases susceptibility to infection in monocotyledenous and dicotyledonous plants. CSEP0064/BEC1054 interacts in planta with five host proteins: two translation elongation factors (eEF1 and eEF1{gamma}), two pathogenesis-related proteins (PR5 and PR10) and a glutathione-S-transferase. We present the first crystal structure of a RALPH, CSEP0064/BEC1054, demonstrating it has an RNase-like fold. The protein interacts with total RNA and weakly with DNA. Methyl jasmonate levels modulate susceptibility to aniline-induced host RNA fragmentation. In planta expression of CSEP0064/BEC1054 reduces the formation of this RNA fragment. We propose that CSEP0064/BEC1054 is a pseudoenzyme that binds to host ribosomes, thereby inhibiting the action of plant ribosome-inactivating proteins that would otherwise lead to host cell death, an unviable interaction and demise of the fungus.

plant biology↗