Volatile profiles of commercial vetch prepared via different processing methods

Vicia sativa (Common Vetch) is currently an underutilised leguminous crop species with high protein content and superior drought tolerance. This study aimed to understand the mechanisms behind vetch flavor development following processing to facilitate its uptake as a future source of dietary protein. A total of 95 volatile compounds were identified by solid-phase microextraction gas chromatography-mass spectrometry (SPME GC–MS) for a range of vetches processed by dehulling, soaking, germination, microwaving, and fermentation. 2-pentyl furan, benzyl alcohol, benzaldehyde, 1-octen-3-ol and 1-hexanol were found to be characteristic aroma compounds of V. sativa. Analysis of a V. sativa landrace demonstrated significant intraspecies variation in volatile abundance, three-fold that of commercial varieties. Both natto and tempeh fermentation produced significant quantities of alcohols, esters, and carboxylic acids with specifically natto generating significant pyrazines. Concentrations of 1-octen-3-ol significantly decreased after tempeh fermentation indicating its potential to reduce documented off flavor generating volatiles within V. sativa

Root angle is controlled by EGT1in cereal crops employing anantigravitropic mechanism

Root angle in crops represents a key trait for efficient capture of soil resources. Root angle is determined by competing gravitropic versus anti-gravitropic offset (AGO) mechanisms. Here we report a new root angle regulatory gene termed ENHANCED GRAVITROPISM1 (EGT1) that encodes a putative AGO component, whose loss of function enhances root gravitropism. Mutations in barley and wheat EGT1 genes confer a striking root phenotype, where every root class adopts a steeper growth angle. EGT1 encodes a F-box and Tubby domain containing protein which is highly conserved across plant species. Haplotype analysis found that natural allelic variation at the barley EGT1 locus impacts root angle. Gravitropic assays indicated that Hvegt1 roots bend more rapidly than wildtype. Transcript profiling revealed Hvegt1 roots deregulate ROS homeostasis and cell wall-loosening enzymes and cofactors. ROS imaging shown that Hvegt1 root basal meristem and elongation zone tissues have reduced levels. Atomic Force Microscopy measurements detected elongating Hvegt1 root cortical cell walls are significantly less stiff than wildtype. In situ analysis identified HvEGT1 is expressed in elongating cortical and stele tissues, which are distinct from known root gravitropic perception and response tissues in the columella and epidermis, respectively. We propose that EGT1 controls root angle by regulating cell wall stiffness in elongating root cortical tissue, counteracting the gravitropic machinery’s known ability to bend the root via its outermost tissues. We conclude that root angle is controlled by EGT1 in cereal crops employing a novel anti-gravitropic mechanism

Understanding Root Growth Dynamics in Plants Under High Temperature Stress

Rapid industrialisation in the last few centuries has led to a significant increase in land temperatures due to the increase in atmospheric concentrations of greenhouse gases. This warming effect increases the frequency of extreme temperature events leading to a higher probability of heat waves, which threaten agricultural output and food security. It is important to study the effects of heat stress on crop productivity, and for that we need a strong understanding of how plants react to elevated temperatures. Currently, we have decades worth of literature on the effects of heat on photosynthesis and reproduction in plants, yet a major component of heat response is still relatively unknown. The root system, aptly known as the ‘hidden half’ of the plant has been shown to sense and react to elevated temperatures but the exact molecular mechanisms of stress response in the root present themselves as a gap in our current understanding. Recent literature suggests that the root system may be more susceptible to higher temperatures than the shoot, and this makes it crucial to understand the effects of high temperature on roots. In this literature review, we discuss the predictions and simulations that point towards a warmer future and what this means for our agricultural system. We explore temperature sensing in roots, an important process, yet the mechanisms of which are still debated. Biochemical and molecular mechanisms of heat response are discussed with a special focus on how the root system has been shown to react to heat stress. Natural variation and genetic improvements in plant heat tolerance, both of which are important tools towards breeding more heat resilient crops, are also considered. This thesis aims to help us better understand the heat stress responses in roots, so that it may aid in breeding more climate proof crops

Understanding Root Growth Dynamics in Plants Under High Temperature Stress

Rapid industrialisation in the last few centuries has led to a significant increase in land temperatures due to the increase in atmospheric concentrations of greenhouse gases. This warming effect increases the frequency of extreme temperature events leading to a higher probability of heat waves, which threaten agricultural output and food security. It is important to study the effects of heat stress on crop productivity, and for that we need a strong understanding of how plants react to elevated temperatures. Currently, we have decades worth of literature on the effects of heat on photosynthesis and reproduction in plants, yet a major component of heat response is still relatively unknown. The root system, aptly known as the ‘hidden half’ of the plant has been shown to sense and react to elevated temperatures but the exact molecular mechanisms of stress response in the root present themselves as a gap in our current understanding. Recent literature suggests that the root system may be more susceptible to higher temperatures than the shoot, and this makes it crucial to understand the effects of high temperature on roots. In this literature review, we discuss the predictions and simulations that point towards a warmer future and what this means for our agricultural system. We explore temperature sensing in roots, an important process, yet the mechanisms of which are still debated. Biochemical and molecular mechanisms of heat response are discussed with a special focus on how the root system has been shown to react to heat stress. Natural variation and genetic improvements in plant heat tolerance, both of which are important tools towards breeding more heat resilient crops, are also considered. This thesis aims to help us better understand the heat stress responses in roots, so that it may aid in breeding more climate proof crops

Ethylene regulates auxin-mediated root gravitropic machinery and controls root angle in cereal crops

Root angle is a critical factor in optimizing the acquisition of essential resources from different soil depths. The regulation of root angle relies on the auxin-mediated root gravitropism machinery. While the influence of ethylene on auxin levels is known, its specific role in governing root gravitropism and angle remains uncertain, particularly when Arabidopsis (Arabidopsis thaliana) core ethylene signaling mutants show no gravitropic defects. Our research, focusing on rice (Oryza sativa L.) and maize (Zea mays), clearly reveals the involvement of ethylene in root angle regulation in cereal crops through the modulation of auxin biosynthesis and the root gravitropism machinery. We elucidated the molecular components by which ethylene exerts its regulatory effect on auxin biosynthesis to control root gravitropism machinery. The ethylene-insensitive mutants ethylene insensitive2 (osein2) and ethylene insensitive like1 (oseil1), exhibited substantially shallower crown root angle compared to the wild type. Gravitropism assays revealed reduced root gravitropic response in these mutants. Hormone profiling analysis confirmed decreased auxin levels in the root tips of the osein2 mutant, and exogenous auxin (NAA) application rescued root gravitropism in both ethylene-insensitive mutants. Additionally, the auxin biosynthetic mutant mao hu zi10 (mhz10)/tryptophan aminotransferase2 (ostar2) showed impaired gravitropic response and shallow crown root angle phenotypes. Similarly, maize ethylene-insensitive mutants (zmein2) exhibited defective gravitropism and root angle phenotypes. In conclusion, our study highlights that ethylene controls the auxin-dependent root gravitropism machinery to regulate root angle in rice and maize, revealing a functional divergence in ethylene signaling between Arabidopsis and cereal crops. These findings contribute to a better understanding of root angle regulation and have implications for improving resource acquisition in agricultural systems

Root angle is controlled by EGT1 in cereal crops employing an antigravitropic mechanism

Root angle in crops represents a key trait for efficient capture of soil resources. Root angle is determined by competing gravitropic versus antigravitropic offset (AGO) mechanisms. Here we report a root angle regulatory gene termed ENHANCED GRAVITROPISM1 (EGT1) that encodes a putative AGO component, whose loss-of-function enhances root gravitropism. Mutations in barley and wheat EGT1 genes confer a striking root phenotype, where every root class adopts a steeper growth angle. EGT1 encodes an F-box and Tubby domain-containing protein that is highly conserved across plant species. Haplotype analysis found that natural allelic variation at the barley EGT1 locus impacts root angle. Gravitropic assays indicated that Hvegt1 roots bend more rapidly than wild-type. Transcript profiling revealed Hvegt1 roots deregulate reactive oxygen species (ROS) homeostasis and cell wall-loosening enzymes and cofactors. ROS imaging shows that Hvegt1 root basal meristem and elongation zone tissues have reduced levels. Atomic force microscopy measurements detected elongating Hvegt1 root cortical cell walls are significantly less stiff than wild-type. In situ analysis identified HvEGT1 is expressed in elongating cortical and stele tissues, which are distinct from known root gravitropic perception and response tissues in the columella and epidermis, respectively. We propose that EGT1 controls root angle by regulating cell wall stiffness in elongating root cortical tissue, counteracting the gravitropic machinery’s known ability to bend the root via its outermost tissues. We conclude that root angle is controlled by EGT1 in cereal crops employing an antigravitropic mechanism