30 research outputs found

    A suberized exodermis is required for tomato drought tolerance.

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    Plant roots integrate environmental signals with development using exquisite spatiotemporal control. This is apparent in the deposition of suberin, an apoplastic diffusion barrier, which regulates flow of water, solutes and gases, and is environmentally plastic. Suberin is considered a hallmark of endodermal differentiation but is absent in the tomato endodermis. Instead, suberin is present in the exodermis, a cell type that is absent in the model organism Arabidopsis thaliana. Here we demonstrate that the suberin regulatory network has the same parts driving suberin production in the tomato exodermis and the Arabidopsis endodermis. Despite this co-option of network components, the network has undergone rewiring to drive distinct spatial expression and with distinct contributions of specific genes. Functional genetic analyses of the tomato MYB92 transcription factor and ASFT enzyme demonstrate the importance of exodermal suberin for a plant water-deficit response and that the exodermal barrier serves an equivalent function to that of the endodermis and can act in its place

    The effect of the triethanolamine: glycerol deep eutectic solvent on the yield, fatty acid composition, antioxidant activity, and physicochemical properties of black mustard (Brassica nigraL.) seed oil

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    This study reports the yields, physicochemical properties, fatty acid compositions, and antioxidant activities of black mustard (Brassica nigraL.) seed oils extracted by cold pressing and the solvent extraction using different solvents (n-hexane, trichloroethylene, and a mixture of trichloroethylene and the triethanolamine:glycerol deep eutectic solvent (TEOA:G DES) with no or after pretreatment with the TEOA:G DES. Density (0.9791 +/- 0.0003-0.9851 +/- 0.0003 g/cm(3)), viscosity (121.15 +/- 1.62-123.32 +/- 0.10 mPas), boiling point (179-185 +/- 1 degrees C), refractive index (1.4692 +/- 0.0006-1.4758 +/- 0.0011), acid (2.08 +/- 0.19-3.22 +/- 0.15 mg KOH/g), iodine (99.2 +/- 1.6-105.4 +/- 1.5 g I-2/100 g), peroxide (1.68 +/- 0.01-1.82 +/- 0.03 mmol O-2/kg), and saponification values (165.1 +/- 2.7-169.4 +/- 2.3 mg KOH/g), fatty acid composition and antioxidant activity of the extracted oil were determined in order to evaluate its potential use as a foodstuff, a pharmaceutical or a feedstock for biodiesel production. Although the maceration of black mustard seeds with sole trichloroethylene yielded the highest oil yield of 31.10 +/- 0.42 g/100 g, it required almost twice the volume of trichloroethylene compared to the volume applied in the macerations after the pre-treatment with the TEOA:G DES and with the mixture of trichloroethylene/TEOA:G DES. The oil extracted by the extraction in the presence of TEOA:G DES has similar physicochemical properties but better antioxidant activity than the oil extracted by cold pressing

    A combination of conserved and diverged responses underlies Theobroma cacao’s defense response to Phytophthora palmivora

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    Abstract Background Plants have complex and dynamic immune systems that have evolved to resist pathogens. Humans have worked to enhance these defenses in crops through breeding. However, many crops harbor only a fraction of the genetic diversity present in wild relatives. Increased utilization of diverse germplasm to search for desirable traits, such as disease resistance, is therefore a valuable step towards breeding crops that are adapted to both current and emerging threats. Here, we examine diversity of defense responses across four populations of the long-generation tree crop Theobroma cacao L., as well as four non-cacao Theobroma species, with the goal of identifying genetic elements essential for protection against the oomycete pathogen Phytophthora palmivora. Results We began by creating a new, highly contiguous genome assembly for the P. palmivora-resistant genotype SCA 6 (Additional file 1: Tables S1-S5), deposited in GenBank under accessions CP139290-CP139299. We then used this high-quality assembly to combine RNA and whole-genome sequencing data to discover several genes and pathways associated with resistance. Many of these are unique, i.e., differentially regulated in only one of the four populations (diverged 40 k–900 k generations). Among the pathways shared across all populations is phenylpropanoid biosynthesis, a metabolic pathway with well-documented roles in plant defense. One gene in this pathway, caffeoyl shikimate esterase (CSE), was upregulated across all four populations following pathogen treatment, indicating its broad importance for cacao’s defense response. Further experimental evidence suggests this gene hydrolyzes caffeoyl shikimate to create caffeic acid, an antimicrobial compound and known inhibitor of Phytophthora spp. Conclusions Our results indicate most expression variation associated with resistance is unique to populations. Moreover, our findings demonstrate the value of using a broad sample of evolutionarily diverged populations for revealing the genetic bases of cacao resistance to P. palmivora. This approach has promise for further revealing and harnessing valuable genetic resources in this and other long-generation plants
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