Peter Hedden

Peter Hedden
Rothamsted Research · Plant Sciences

Bachelor of Science, PhD

About

300
Publications
57,308
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20,430
Citations
Citations since 2017
19 Research Items
8107 Citations
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400

Publications

Publications (300)
Article
Full-text available
Background Bread wheat ( Triticum aestivum ) is a major source of nutrition globally, but yields can be seriously compromised by water limitation. Redistribution of growth between shoots and roots is a common response to drought, promoting plant survival, but reducing yield. Gibberellins (GAs) are necessary for shoot and root elongation, but roots...
Preprint
Full-text available
Background Bread wheat (Triticum aestivum) is a major source of nutrition globally, but yields can be seriously compromised by water limitation. Redistribution of growth between shoots and roots is a common response to drought, promoting plant survival, but reducing yield. Gibberellins (GAs) are necessary for shoot and root elongation, but roots ma...
Article
Nitrate, one of the main nitrogen (N) sources for crops, acts as a nutrient and key signaling molecule coordinating gene expression, metabolism, and various growth processes throughout the plant life cycle. It is widely accepted that nitrate-triggered developmental programs cooperate with hormone synthesis and transport to finely adapt plant archit...
Preprint
Nitrate, one of the main nitrogen (N) sources for crops, acts as a nutrient and key signaling molecule coordinating gene expression, metabolism and various growth processes throughout the plant life cycle. It is widely accepted that nitrate-triggered developmental programs cooperate with hormone synthesis and transport, to finely adapt plant archit...
Article
Full-text available
Increased mechanical impedance induced by soil drying or compaction causes reduction in plant growth and crop yield. However, how mechanical impedance interacts with nutrient stress has been largely unknown. Here, we investigated the effect of mechanical impedance on the growth of wheat seedlings under contrasting phosphorus (P) supply in a sand cu...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Full-text available
Root elongation depends on the action of the gibberellin (GA) growth hormones, which promote cell production in the root meristem and cell expansion in the elongation zone. Sites of GA biosynthesis in the roots of 7 day‐old Arabidopsis thaliana seedlings were investigated using tissue‐specific GA inactivation in wild type (Col‐0) or rescue of GA‐de...
Article
Full-text available
Gibberellins are produced by all vascular plants as well as several fungal and bacterial species that associate with plants as pathogens or symbionts. In the 60 years since the first experiments on the biosynthesis of gibberellic acid in the fungus Fusarium fujikuroi, research on gibberellin biosynthesis has advanced to provide detailed information...
Article
A previously unknown biologically active gibberellin present in seeds of Arabidopsis thaliana is formed by hydration of the gibberellin precursor GA12 through the action of GAS2, a 2-oxoglutarate-dependent dioxygenase that decreases sensitivity to abscisic acid and promotes seed germination and seedling establishment.
Article
Full-text available
Key message: Linear modelling approaches detected significant gradients in organ growth and patterning across early flowers of the Arabidopsis inflorescence and uncovered evidence of new roles for gibberellin in floral development. Most flowering plants, including the genetic model Arabidopsis thaliana, produce multiple flowers in sequence from a...
Article
Most flowering plants, including the genetic model Arabidopsis thaliana, produce multiple flowers in sequence from a reproductive shoot apex to form a flower spike (inflorescence). The development of individual flowers on an Arabidopsis inflorescence has typically been considered as highly stereotypical and uniform, but this assumption is contradic...
Article
Gibberellins (GAs) are crucial phytohormones involved in many aspects of plant growth and development, including plant–microbe interactions, which has led to GA production by plant-associated fungi and bacteria as well. While the GA biosynthetic pathways in plants and fungi have been elucidated and found to have arisen independently through converg...
Article
Full-text available
Significance Understanding how hormones like auxin control plant growth and development has fascinated scientists since Darwin. The past two decades have seen breakthroughs in elucidating the molecular basis of auxin transport, perception, and response, but little is known about how auxin is metabolized or its homeostasis is controlled. We report t...
Chapter
The gibberellins (GAs) comprise a large group of tetracyclic diterpenoid carboxylic acids, first discovered as secondary metabolites of the fungus Fusarium fujikuroi. They are now known to be produced by vascular plants and a number of fungal and bacterial species. Their biosynthesis in plants, fungi, and bacteria is well characterized, with substa...
Book
First discovered as fungal metabolites, the gibberellins were recognised as plant hormones over 50 years ago. They regulate reproductive development in all vascular plants, while their role in flowering plants has broadened to include also the regulation of growth and other developmental processes. This timely book covers the substantial and impres...
Chapter
Biosynthesis of the major biologically active gibberellins (GAs) in higher plants proceeds first in plastids via the tetracyclic diterpene hydrocarbon ent-kaurene, which is oxidised by membrane-associated cytochrome P450 mono-oxygenases to produce GA12 and GA53 on the endoplasmic reticulum. These intermediates are oxidised further by the soluble 2-...
Article
We argue that the well-known effects of increasing pressure with depth due to the weight of soil (called surcharge) makes the soil so strong that roots can elongate to deeper layers only if they can locate existing pore networks. At depths as shallow as 50 cm, increases in soil strength, even in well-watered soil, are so great that root elongation...
Article
Full-text available
Gibberellin research has its origins in Japan in the 19th century, when a disease of rice was shown to be due to a fungal infection. The symptoms of the disease including overgrowth of the seedling and sterility were later shown to be due to secretions of the fungus Gibberella fujikuroi (now reclassified as Fusarium fujikuroi), from which the name...
Article
Full-text available
Global inspection of plant genomes identifies genes maintained in low copies across taxa and under strong purifying selection. Those are likely to have essential functions. Based on this rational, we investigated the function of the low-duplicated CYP715 cytochrome P450 gene family that appeared early in seed plants and evolved under strong negativ...
Article
Full-text available
Background The gibberellin (GA) pathway plays a central role in the regulation of plant development, with the 2-oxoglutarate-dependent dioxygenases (2-ODDs: GA20ox, GA3ox, GA2ox) that catalyse the later steps in the biosynthetic pathway of particularly importance in regulating bioactive GA levels. Although GA has important impacts on crop yield and...
Article
Full-text available
The gibberellin (GA) phytohormones play important roles in plant growth and development, promoting seed germination, elongation growth and reproductive development. Over the years, substantial progress has been made in understanding the regulation of GA signalling and metabolism, which ensures appropriate levels of GAs for growth and development. M...
Chapter
Since the discovery of the first examples of 2-oxoglutarate-dependent oxygenase-catalysed reactions in the 1960s, a remarkably broad diversity of alternate reactions and substrates has been revealed, and extensive advances have been achieved in our understanding of the structures and catalytic mechanisms. These enzymes are important agrochemical ta...
Article
Jake MacMillan, who died on May 12, 2014 at the age of 89, was an organic chemist who made an enormous contribution to plant science, particularly in relation to the structure, biosynthesis, and analysis of the gibberellin plant hormones. Jake was born in Wishaw, Scotland, into a lower working class environment in which there was very little spare...
Article
During germination of cereal grain, α-amylase formation is known to be inhibited by abscisic acid (ABA) and stimulated by gibberellins (GA). The role of these hormones in pre-maturity α-amylase (PMA) formation in wheat grains is less well understood. Our previous work with ABA and GA exogenously applied to grains demonstrated a clear stimulatory ef...
Article
Full-text available
To study the role of abscisic acid (ABA) and gibberellins (GA) in pre-maturity α-amylase (PMA) formation in developing wheat grain, two glasshouse experiments were conducted under controlled conditions in the highly PMA-susceptible genotype Rialto. The first, determined the relative efficacy of applying hormone solutions by injection into the pedun...
Article
Full-text available
Excessive gibberellin (GA) signalling, mediated through the DELLA proteins, has a negative impact on plant fertility. Loss of DELLA activity in the monocot rice (Oryza sativa) causes complete male sterility, but not in the dicot model Arabidopsis (Arabidopsis thaliana) ecotype Landsberg erecta (Ler), in which DELLA function has been studied most ex...
Article
Plants survive adverse conditions by modulating their growth in response to a changing environment. Gibberellins (GAs) play a key role in these adaptive responses by stimulating the degradation of growth-repressing DELLA proteins. GA binding to its receptor GID1 enables association of GID1 with DELLAs. This leads to the ubiquitin-mediated proteasom...
Article
Full-text available
Plant hormones are small molecules that regulate plant growth and development, as well as responses to changing environmental conditions. By modifying the production, distribution or signal transduction of these hormones, plants are able to regulate and coordinate both growth and/or stress tolerance to promote survival or escape from environmental...
Article
To study the role of abscisic acid (ABA) and gibberellin (GA) sensitivity in regulating pre-maturity α-amylase (PMA) in wheat grains, plants were grown in a glasshouse under cold-shock and ambient conditions. α-amylase activity in response to applied ABA and GA was measured in detached-grains with the embryo removed (in vitro) and in intact-grains...
Data
Loss of REPRESSOR OF ga1-3 (RGA) and GIBBERELLIN INSENSITIVE (GAI) causes infertility in the Col-0 background. Fig. S2 Effect of gibberellin (GA) treatment on silique set and floral organ growth. Fig. S3 Comparison of gid1a-1 gid1b-1 gid1c-1 and gid1a-1 gid1b-1 gid1c-2 phenotypes. Fig. S4 The Ler DELLA global mutant retains pollen viability. Fig. S...
Article
Full-text available
Background and aims The concept of root-sourced chemical signals that affect shoot growth in response to drought is widely reported; in particular the role of ABA in regulating stomatal conductance has received much attention. ABA, alone, does not fully explain all the effects of abiotic stresses in the root zone on shoot architecture. An increase...
Article
Eragrostis tef (Zucc.) Trotter, a tetraploid cereal of Ethiopia, has a tall and slender stem that is susceptible to lodging, causing yield loss of ˜15%–45% each year. Genes conferring lodging resistance through the control of plant height involves gibberellins (GA) metabolism genes that have not been identified and characterized in E. tef. The aim...
Article
Full-text available
A robust, reliable and high-throughput method for extraction and purification of gibberellins (GAs), a group of tetracyclic diterpenoid carboxylic acids that include endogenous growth hormones, from plant material was developed. The procedure consists of two solid-phase extraction steps (Oasis(®) MCX-HLB and Oasis(®) MAX) and gives selective enrich...
Article
Full-text available
Root-knot nematodes are obligate parasites that invade roots and induce the formation of specialized feeding structures. Although physiological and molecular changes inside the root leading to feeding site formation have been studied, very little is known about the molecular events preceding root penetration by nematodes. In order to investigate th...
Data
Transcript-derived fragments sequences. (DOCX)
Data
Mean ΔCT for statistical comparison. LSD = Least significant difference, degree of freedom (df) = 19 except for P16EF1 and P17AB3 (df = 18) (DOCX)
Data
Summary of the 63 transcript-derived fragments (TDF)a. a Differential expression between ARE- and H2O-treated Meloidogyne incognita infective juveniles b Presence (Y) or absence (N) of signal peptide (SP) was determined by using SignalP software. When no full cDNA or protein sequence was available, the presence of a SP was not determined (Na). c Pu...
Data
Gene expression analysis of MAP-1 and 2 selected TDFs during the A. thaliana - M. icognita interaction using different endogenous gene: Gene expression analysis by qRT-PCR of A, MAP-1 , B, P57E2 and C, P16AB6 during the pathogenic interaction (1 biological repeat) using 3 different endogenous reference genes: actin, elongation factor 1...
Data
Oligonucleotides used for qRT-PCR. (DOCX)
Article
Full-text available
Effects of in situ and in vitro applied abscisic acid (ABA) and gibberellic acid (GA3) on pre-maturity α-amylase (PMA) were investigated in glasshouse experiments under cool-temperature shock-induced and non-induced conditions using UK winter wheat varieties, Spark (low PMA susceptible) and Rialto (high PMA susceptible). In the in situ study, hormo...
Article
Full-text available
Fruit-set and growth in tomato depend on the action of gibberellins (GAs). To evaluate the role of the GA biosynthetic enzyme GA 20-oxidase (GA20ox) in that process, the citrus gene CcGA20ox1 was overexpressed in tomato (Solanum lycopersicum L.) cv Micro-Tom. The transformed plants were taller, had non-serrated leaves, and some flowers displayed a...
Article
Full-text available
The biosynthesis of gibberellic acid (GA(3)) by the fungus Fusarium fujikuroi is catalyzed by seven enzymes encoded in a gene cluster. While four of these enzymes are characterized as cytochrome P450 monooxygenases, the nature of a fifth oxidase, GA(4) desaturase (DES), is unknown. DES converts GA(4) to GA(7) by the formation of a carbon-1,2 double...
Chapter
The gibberellins are a large class of tetracyclic diterpenoid carboxylic acids, which are present in flowering plants, as well as some species of lower plants, fungi and bacteria. They include endogenous growth regulators in higher plants, in which they promote organ growth and induce certain developmental switches. Production of the biologically a...
Article
Full-text available
Over the next decade, wheat grain production must increase to meet the demand of a fast growing human population. One strategy to meet this challenge is to raise wheat productivity by optimizing plant stature. The Reduced height 8 (Rht8) semi-dwarfing gene is one of the few, together with the Green Revolution genes, to reduce stature of wheat (Trit...
Article
Full-text available
Sugar-beet crops, Beta vulgaris spp. vulgaris (L), suffer from premature bolting and flowering as a consequence of prolonged exposure to cold conditions (vernalization). This reduces crop yield and quality and could be avoided if bolting-resistant varieties were available. Traditionally, development of bolting-resistant varieties has relied on sele...
Article
Fusarium fujikuroi and Fusarium proliferatum are two phylogenetically closely related species of the Gibberella fujikuroi species complex (GFC). In some cases, strains of these species can cross and produce a few ascospores. In this study, we analyzed 26 single ascospore isolates of an interspecific cross between F. fujikuroi C1995 and F. prolifera...
Article
Full-text available
The GAs (gibberellins) comprise a large group of diterpenoid carboxylic acids that are ubiquitous in higher plants, in which certain members function as endogenous growth regulators, promoting organ expansion and developmental changes. These compounds are also produced by some species of lower plants, fungi and bacteria, although, in contrast to hi...
Article
Eragrostis tef, a tall stature and highly nutritious cereal grown in East Africa, has a serious lodging problem that reduces its productivity considerably. Certain plant-growth regulators are known to restrict growth and consequently improve lodging resistance in cereals by affecting gibberellin biosynthesis. The effect on height of growth regulato...
Article
Full-text available
RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author mu...
Article
Full-text available
The hormone gibberellin (GA) is a key regulator of plant growth. Many of the components of the gibberellin signal transduction [e.g., GIBBERELLIN INSENSITIVE DWARF 1 (GID1) and DELLA], biosynthesis [e.g., GA 20-oxidase (GA20ox) and GA3ox], and deactivation pathways have been identified. Gibberellin binds its receptor, GID1, to form a complex that m...
Article
Full-text available
Sugar beet (Beta vulgaris sp. vulgaris) crops account for about 30% of world sugar. Sugar yield is compromised by reproductive growth hence crops must remain vegetative until harvest. Prolonged exposure to cold temperature (vernalization) in the range 6 °C to 12 °C induces reproductive growth, leading to bolting (rapid elongation of the main stem)...
Data
Differentially expressed loci for C600 vs Roberta genotypes.
Data
List of gene loci that are positively and negatively correlated with BvRAV1-like at a probability of p > 0.95.
Data
Gene Ontology and InterPro Domain enrichment analyses. For genes that are negatively correlated with BvRAV1 together with their associated candidates as revealed by network analysis using AraNet.
Data
DGE tag count matrix for all loci. Normalized DGE profile tag counts for all loci with a count of 10 in at least one of the test samples.