Biology subjects

Cesco, S.

Publications and source records attributed to Cesco, S..

4 recordsLinked to original sources

bioRxiv2025

Double knockout of rice OsVIT1 and OsVIT2 genes reveals a trade-off between iron biofortification and iron excess tolerance

Rice (Oryza sativa L.) is a staple food for half of the worlds population, but lacks essential nutrients such as iron (Fe). Fe deficiency is one of the most common nutritional problems in humans, and biofortification of rice grains is a cost-effective approach to deliver more Fe to peoples diet. Two Vacuolar Iron Transporters, OsVIT1 and OsVIT2, were shown to negatively regulate Fe translocation to rice developing panicles, as single mutants osvit1 and osvit2 have increased Fe concentration in seeds. Importantly, rice plants are frequently cultivated in waterlogged soils that are highly reductive and prone to Fe3+ reduction to the more soluble Fe2+, which can accumulate and cause Fe toxicity. Little is known about which genes control Fe excess detoxification. OsVIT1 and OsVIT2 transport Fe into the vacuole, and OsVIT2 is induced under Fe excess, but whether they play a role in Fe detoxification was not demonstrated. We generated double mutants osvit1osvit2 using CRISPR-Cas9 to test whether loss of function of both genes could increase Fe concentration in seeds, and to test whether their loss of function has impact in rice Fe excess tolerance. We showed that osvit1osvit2 double mutants accumulated more Fe in brown rice. Fe accumulation was clear in embryo scutellum and plumule, suggesting VIT transporters have a role in determining Fe spatial distribution. We also showed that root uptake contributed significantly for increased Fe accumulation in osvit1osvit2 seeds, suggesting OsVIT1 and OsVIT2 are involved in sequestering Fe in vegetative tissues and decreasing translocation. Strikingly, we found that osvit1osvit2 plants were more sensitive to Fe excess, revealing a trade-off between Fe biofortification and Fe excess tolerance. Our data indicates OsVIT1 and OsVIT2 are key for Fe excess detoxification, which should be considered in their use as targets for biofortification.

plant biology↗

bioRxiv2021

Identification of an isoflavonoid transporter required for the nodule establishment of the Rhizobium-Fabaceae symbiotic interaction

Nitrogen (N) as well as Phosphorus (P) are key nutrients determining crop productivity. Legumes have developed strategies to overcome nutrient limitation by e.g., forming a symbiotic relationship with N-fixing rhizobia and the release of P-mobilizing exudates and are thus able to grow without supply of N or P fertilizers. The legume-rhizobial symbiosis starts with root release of isoflavonoids, that act as signaling molecules perceived by compatible bacteria. Subsequently, bacteria release nod factors, which induce signaling cascades allowing the formation of functional N-fixing nodules. We report here the identification and functional characterization of a plasma membrane-localized MATE-type transporter (LaMATE2) involved in the release of genistein from white lupin roots. The LaMATE2 expression in the root is upregulated under N deficiency as well as low phosphate availability, two nutritional deficiencies that induce the release of this isoflavonoid. LaMATE2 silencing reduced genistein efflux and even more the formation of symbiotic nodules, supporting the crucial role of LaMATE2 in isoflavonoid release and nodulation. Furthermore, silencing of LaMATE2 limited the P-solubilization activity of lupin root exudates. Transport assays in yeast vesicles demonstrated that LaMATE2 acts as a proton-driven isoflavonoid transporter.

plant biology↗

bioRxiv2021

The hidden effects of agrochemicals on plant metabolism and root-associated microorganisms

Agrochemicals are commonly used in agriculture to protect crops and ensure yields. Several of them are mobile within the plant and, being perceived as xenobiotics regardless of their protective/curative roles, they induce a reprogramming of secondary metabolism linked to the detoxification processes even in the absence of phenotype symptoms. Moreover, it is well documented that plants, thanks to the root exudation of different metabolites, are able to shape the microbial population at the rhizosphere and to significantly affect the processes occurring therein. Here we show that plant metabolic response to foliarly-applied pesticides is much broader than what previously thought and includes diverse and compound-specific hidden processes. Among others, stress-related metabolism and phytohormones profile underwent a considerable reorganization. Moreover, a distinctive microbial rearrangement of the rhizosphere was recorded following foliar application of pesticides. Such effects have unavoidably energetic and metabolic costs for the plant paving the way to both positive and negative aspects. The understanding of these effects is crucial for an increasingly sustainable use of pesticides in agriculture. HighlightThe foliar application of pesticides induces a broad metabolic reprogramming in plant and shapes the microbial population of the rhizosphere.

plant biology↗

bioRxiv2020

Millimeter-resolution mapping of citrate exuded from soil grown roots using a novel, low-invasive sampling technique

The reliable sampling of root exudates in soil grown plants is experimentally challenging. This study aimed at developing a citrate sampling and mapping technique with millimetre-resolution using DGT (diffusive gradients in thin films) ZrOH binding gels. Citrate adsorption kinetics, DGT capacity and stability of ZrOH gels were evaluated. ZrOH gels were applied to generate 2D maps of citrate exuded by white lupin roots grown in rhizotrosn in a phosphorus deficient soil. Citrate was adsorbed quantitatively and rapidly by the ZrOH gels, these gels can be stored after sampling for several weeks prior to analysis. The DGT capacity of the ZrOH gel for citrate depends on the ionic strength and the pH of the soil solution but was suitable for citrate sampling. 2D citrate maps of rhizotron grown plants have been generated for the first time at a millimetre resolution to measure an illustrated plant response to P fertilization. DGT-based citrate sampling is suitable for studying the root exudation in soil environments, at unprecedented spatial resolution. By changing binding material, the technique is also applicable to other exudate classes and might be used for the evaluation of whole root exudation crucial in specific cultivar breeding. HighlightWe present a novel, reliable, easy to use, non-destructive citrate sampling- and two-dimensional high-resolution imaging technique for soil grown plant roots.

plant biology↗