ORCID Profile
0000-0002-9178-7050
Current Organisations
Københavns Universitet
,
University of Nottingham
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Publisher: MDPI AG
Date: 04-08-2022
Abstract: Flooding is constantly threatening the growth and yield of crops worldwide. When flooding kicks in, the soil becomes water-saturated and, therefore, the roots are the first organs to be exposed to excess water. Soon after flooding, the soil turns anoxic and the roots can no longer obtain molecular oxygen for respiration from the rhizosphere, rendering the roots dysfunctional. Rice, however, is a semi-aquatic plant and therefore relatively tolerant to flooding due to adaptive traits developed during evolution. In the present review, we have identified three key root traits, viz. cortical aerenchyma formation, a barrier to radial oxygen loss and adventitious root growth. The understanding of the physiological function, the molecular mechanisms, and the genetic regulation of these three traits has grown substantially and therefore forms the backbone of this review. Our synthesis of the recent literature shows each of the three key root traits contributes to flood tolerance in rice. One trait, however, is generally insufficient to enhance plant tolerance to flooding. Consequently, we suggest comprehensive use of all three adaptive traits in a pyramiding approach in order to improve tolerance to flooding in our major crops, in general, and in rice, in particular.
Publisher: Wiley
Date: 11-01-2023
DOI: 10.1111/NPH.18678
Abstract: A key trait conferring flood tolerance is the ability to grow adventitious roots as a response to submergence. The genetic traits of deepwater rice determining the development and characteristics of aquatic adventitious roots (AAR) had not been evaluated. We used near‐isogenic lines introgressed to test the hypothesis that the impressive shoot elongation ability of deepwater rice linked to quantitative trait loci 1 and 12 also promote the development of AAR. The deepwater rice genotype NIL‐12 possessed expanded regions at the stem nodes where numerous AAR developed as a response to submergence. Two types (AR1 and AR2) of roots with distinct timing of emergence and large differences in morphological and anatomical traits formed within 3 (AR1) to 7 (AR2) d of submergence. The mechanical impedance provided by the leaf sheath caused AR2 to emerge later promoting thicker roots, higher elongation capacity and higher desiccation tolerance. Upregulation of key genes suggests a joint contribution in activating the meristem in AAR enhancing the development of these in response to submergence. The morphological and anatomical traits suggested that AR2 is better adapted to long‐term flooding than AR1. We therefore propose that AR2 in deepwater rice functions as an evolutionary defence strategy to tackle periodic submergence.
Publisher: CSIRO Publishing
Date: 2023
DOI: 10.1071/FP23133
Publisher: Springer Science and Business Media LLC
Date: 11-10-2023
Publisher: Wiley
Date: 26-07-2019
DOI: 10.1111/PLB.13029
Abstract: Hypoxic floodwaters can seriously damage seedlings. Seed dormancy could be an effective trait to avoid lethal underwater germination. This research aimed to discover novel adaptive dormancy responses to hypoxic floodwaters in seeds of Echinochloa crus-galli, a noxious weed from rice fields and lowland croplands. Echinochloa crus-galli dormant seeds were subjected to a series of sequential treatments. Seeds were: (i) submerged under hypoxic floodwater (simulated with hypoxic flasks) at different temperatures for 15 or 30 days, and germination tested under drained conditions while exposing seeds to dormancy-breaking signals (alternating temperatures, nitrate (KNO
Publisher: Springer Science and Business Media LLC
Date: 29-09-2023
DOI: 10.1007/S11104-022-05711-Y
Abstract: Root tissue water can be lost to the dry topsoil via radial water loss (RWL) resulting in root shrinking and loss of contact with the rhizosphere. The root barrier to radial oxygen loss (ROL) has been shown to restrict RWL, therefore we hypothesized that the inducible barrier can be formed as a response to low soil water potential and play a role, together with other root traits, in restricting RWL. Rice and wheat were grown in hydroponics with contrasting water potential to diagnose ROL barrier formation and to explore how key root traits (ROL barrier, root diameter, root porosity) affect RWL. Moreover, we developed a numerical model predicting RWL as a function of root diameter, root porosity and presence of a barrier to ROL. Methylene blue staining showed that low water potential induced a ROL barrier formation in roots of rice, and also resulted in an apoplastic barrier, as identified by the apoplastic tracer periodic acid. The barrier significantly restricted RWL, but root diameter and tissue porosity also influenced RWL. Our numerical model was able to reflect the empirical data and clearly demonstrated that thick roots and a barrier to ROL restricts RWL while cortical porosity accelerates RWL. Our modelling approach highlighted that increase in root tissue porosity, a common response to drought, conserves water when new roots are formed, but the higher desiccation risk related to high-porosity roots can be effectively counteracted by forming thick roots or even better, by a barrier to ROL.
Publisher: Oxford University Press (OUP)
Date: 11-01-2023
DOI: 10.1093/JXB/ERAD014
Abstract: Excess water can induce flooding stress resulting in yield loss, even in wetland crops such as rice (Oryza). However, traits from species of wild Oryza have already been used to improve tolerance to abiotic stress in cultivated rice. This study aimed to establish root responses to sudden soil flooding among eight wild relatives of rice with different habitat preferences benchmarked against three genotypes of O. sativa. Plants were raised hydroponically, mimicking drained or flooded soils, to assess the plasticity of adventitious roots. Traits included were apparent permeance (PA) to O2 of the outer part of the roots, radial water loss, tissue porosity, apoplastic barriers in the exodermis, and root anatomical traits. These were analysed using a plasticity index and hierarchical clustering based on principal component analysis. For ex le, O. brachyantha, a wetland species, possessed very low tissue porosity compared with other wetland species, whereas dryland species O. latifolia and O. granulata exhibited significantly lower plasticity compared with wetland species and clustered in their own group. Most species clustered according to growing conditions based on PA, radial water loss, root porosity, and key anatomical traits, indicating strong anatomical and physiological responses to sudden soil flooding.
Publisher: Wiley
Date: 21-06-2021
DOI: 10.1111/NPH.17474
Abstract: The root barrier to radial O 2 loss (ROL) is a trait enabling waterlogging tolerance of plants. The ROL barrier restricts O 2 diffusion to the anoxic soil so that O 2 is retained inside root tissues. We hypothesised that the ROL barrier can also restrict radial diffusion of other gases (H 2 and water vapour) in rice roots with a barrier to ROL. We used O 2 and H 2 microsensors to measure ROL and permeability of rice roots, and gravimetric measurements to assess the influence of the ROL barrier on radial water loss (RWL). The ROL barrier greatly restricted radial diffusion of O 2 as well as H 2 . At 60 kPa p O 2 , we found no radial diffusion of O 2 across the barrier, and for H 2 the barrier reduced radial diffusion by 73%. Similarly, RWL was reduced by 93% in roots with a ROL barrier. Our study showed that the root barrier to ROL not only completely blocks radial O 2 diffusion under steep concentration gradients but is also a diffusive barrier to H 2 and to water vapour. The strong correlation between ROL and RWL presents a case in which simple measurements of RWL can be used to predict ROL in screening studies with a focus on waterlogging tolerance.
Publisher: Wiley
Date: 07-04-2023
DOI: 10.1111/NPH.18883
Abstract: The root barrier to radial O 2 loss (ROL) is a key root trait preventing O 2 loss from roots to anoxic soils, thereby enabling root growth into anoxic, flooded soils. We hypothesized that the ROL barrier can also prevent intrusion of hydrogen sulphide (H 2 S), a potent phytotoxin in flooded soils. Using H 2 S‐ and O 2 ‐sensitive microsensors, we measured the apparent permeance to H 2 S of rice roots, tested whether restricted H 2 S intrusion reduced its adverse effects on root respiration, and whether H 2 S could induce the formation of a ROL barrier. The ROL barrier reduced apparent permeance to H 2 S by almost 99%, greatly restricting H 2 S intrusion. The ROL barrier acted as a shield towards H 2 S O 2 consumption in roots with a ROL barrier remained unaffected at high H 2 S concentration (500 μM), compared to a 67% decline in roots without a barrier. Importantly, low H 2 S concentrations induced the formation of a ROL barrier. In conclusion, the ROL barrier plays a key role in protecting against H 2 S intrusion, and H 2 S can act as an environmental signalling molecule for the induction of the barrier. This study demonstrates the multiple functions of the suberized/lignified outer part of the rice root beyond that of restricting ROL.
Publisher: Oxford University Press (OUP)
Date: 18-11-2021
DOI: 10.1093/JXB/ERAA542
Abstract: Flooding is an environmental stress that leads to a shortage of O2 that can be detrimental for plants. When flooded, deepwater rice grow floating adventitious roots to replace the dysfunctional soil-borne root system, but the features that ensure O2 supply and hence growth of aquatic roots have not been explored. We investigate the sources of O2 in aquatic adventitious roots and relate aerenchyma and barriers for gas diffusion to local O2 gradients, as measured by microsensor technology, to link O2 distribution in distinct root zones to their anatomical features. The mature root part receives O2 exclusively from the stem. It has aerenchyma that, together with suberin and lignin depositions at the water–root and cortex–stele interfaces, provides a path for longitudinal O2 movement toward the tip. The root tip has no diffusion barriers and receives O2 from the stem and floodwater, resulting in improved aeration of the root tip over mature tissues. Local formation of aerenchyma and diffusion barriers in the mature root channel O2 towards the tip which also obtains O2 from the floodwater. These features explain aeration of floating roots and their ability to grow under water.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Lucas León Peralta Ogorek.