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Summary: Sweet sorghum accumulates large amounts of soluble sugar in its stem. However, a system‐based understanding of this carbohydrate allocation process is lacking. Here, we compared the dynamic transcriptome and metabolome between the conversion line R9188 and its two parents, sweet sorghum RIO and grain sorghum BTx406 that have contrasting sugar‐accumulating phenotypes. We identified two features of sucrose metabolism, stable concentrations of sugar phosphates in RIO and opposite trend of trehalose‐6‐phosphate (T6P) between RIO vs R9188/BTx406. Integration of transcriptome and metabolome revealed R9188 is partially active in starch metabolism together with medium sucrose level, whereas sweet sorghum had the highest sucrose concentration and remained highly active in sucrose, starch, and cell wall metabolism post‐anthesis. Similar expression pattern of genes involved in sucrose degradation decreased the pool of sugar phosphates for precursors of starch and cell wall synthesis in R9188 and BTx406. Differential T6P signal between RIO vs R9188/BTx406 is associated with introgression of T6P regulators from BTx406 into R9188, including C‐group bZIP and trehalose 6‐phosphate phosphatase (TPP). The inverted T6P signalling in R9188 appears to down‐regulate sucrose and starch metabolism partly through transcriptome reprogramming, whereas introgressed metabolic genes could be related to reduced cell wall metabolism. Our results show that coordinated primary metabolic pathways lead to high sucrose demand and accumulation in sweet sorghum, providing us with targets for genetic improvements of carbohydrate allocation in bioenergy crops. [ABSTRACT FROM AUTHOR]

Examines the molecular regulation of nectary development. Use of reverse transcriptase-polymerase chain reaction in cloning of NEC1, a gene expressed in the nectaries of Petunia hybrida; Presence of NEC1 protein in the nectaries; Role of NEC1 gene in sugar metabolism and nectar secretion.

Summary:The molecular and genetic control of inflorescence and flower development has been studied in great detail in model dicotyledonous plants such asArabidopsisandAntirrhinum. In contrast, little is known about these important developmental steps in monocotyledonous species. Here we report the analysis of theZea maysmutantbranched silkless1–2 (bd1–2), allelic tobd1, which we have used as a tool to study the transition from spikelet to floret development in maize. Floret development is blocked in the female inflorescence (the ear) ofbd1–2plants, whereas florets develop almost normally in the male inflorescence (the tassel). Detailed phenotypic analyses indicate that inbd1–2mutants ear inflorescence formation initiates normally, however, the spikelet meristems do not proceed to form floret meristems. The ear spikelets, at anthesis, contain various numbers of spikelet-like meristems and glume-like structures. Furthermore, growth of branches from the base of the ear is often observed. Expression analyses show that the floral-specific MADS box genesZea mays AGAMOUS1(ZAG1), ZAG2 andZea mays MADS 2(ZMM2) are not expressed in ear florets inbd1–2mutants, whereas their expression in tassel florets is similar to that of wild type. Taken together, these data indicate that the development from spikelet to floret meristem is differentially controlled in the ear and tassel in the monoecious grass speciesZea mays, and thatBRANCHED SILKLESSplays an important role in regulating the transition from spikelet meristem to floral meristem during the development of the female inflorescence of maize.. [ABSTRACT FROM AUTHOR]

Asymmetry of investment in crop research leads to knowledge gaps and lost opportunities to accelerate genetic gain through identifying new sources and combinations of traits and alleles. On the basis of consultation with scientists from most major seed companies, we identified several research areas with three common features: (i) relatively underrepresented in the literature; (ii) high probability of boosting productivity in a wide range of crops and environments; and (iii) could be researched in 'precompetitive' space, leveraging previous knowledge, and thereby improving models that guide crop breeding and management decisions. Areas identified included research into hormones, recombination, respiration, roots, and source–sink, which, along with new opportunities in phenomics, genomics, and bioinformatics, make it more feasible to explore crop genetic resources and improve breeding strategies. More symmetrical investment in crop research will create opportunities to improve crop models, combine new alleles through prebreeding, and suggest novel crop management practices. Consensus among public and private sectors is that more investment is needed to improve understanding of hormone crosstalk, recombination rate, maintenance respiration, root structure and function, and source–sink balance. Greater investment in these areas is expected to benefit a wide range of crops across most environments. New opportunities in phenomics, genomics, and bioinformatics make it feasible to explore the vast untapped collections of crop genetic resources to create novel trait combinations. Filling knowledge gaps is expected to enable a much more integrated understanding of crop yield and adaptation, improving breeding and crop management models. [ABSTRACT FROM AUTHOR]

Crop productivity needs to substantially increase to meet global food and feed demand for a rapidly growing world population. Agricultural technology developers are pursuing a variety of approaches based on both traditional technologies such as genetic improvement, pest control and mechanization as well as new technologies such as genomics, gene manipulation and environmental modelling to develop crops that are capable of meeting growing demand. Photosynthesis is a key biochemical process that, many suggest, is not yet optimized for industrial agriculture or the modern global environment. We are interested in identifying control points in maize photoassimilation that are amenable to gene manipulation to improve overall productivity. Our approach encompasses: developing and using novel gene discovery techniques, translating our discoveries into traits and evaluating each trait in a stepwise manner that reflects a modern production environment. Our aim is to provide step change advancement in overall crop productivity and deliver this new technology into the hands of growers.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'., (© 2017 The Author(s).)