Challenges and prospects of new plant breeding techniques for GABA improvement in crops: tomato as an example

[EN] Over the last seven decades, gamma-aminobutyric acid (GABA) has attracted great attention from scientists for its ubiquity in plants, animals and microorganisms and for its physiological implications as a signaling molecule involved in multiple pathways and processes. Recently, the food and pharmaceutical industries have also shown significantly increased interest in GABA, because of its great potential benefits for human health and the consumer demand for health-promoting functional compounds, resulting in the release of a plethora of GABA-enriched products. Nevertheless, many crop species accumulate appreciable GABA levels in their edible parts and could help to meet the daily recommended intake of GABA for promoting positive health effects. Therefore, plant breeders are devoting much effort into breeding elite varieties with improved GABA contents. In this regard, tomato (Solanum lycopersicum), the most produced and consumed vegetable worldwide and a fruit-bearing model crop, has received much consideration for its accumulation of remarkable GABA levels. Although many different strategies have been implemented, from classical crossbreeding to induced mutagenesis, new plant breeding techniques (NPBTs) have achieved the best GABA accumulation results in red ripe tomato fruits along with shedding light on GABA metabolism and gene functions. In this review, we summarize, analyze and compare all the studies that have substantially contributed to tomato GABA breeding with further discussion and proposals regarding the most recent NPBTs that could bring this process to the next level of precision and efficiency. This document also provides guidelines with which researchers of other crops might take advantage of the progress achieved in tomato for more efficient GABA breeding programsPG is grateful to the Japanese Society for the Promotion of Science for the JSPS postdoctoral grant FY2019-P19105Gramazio, P.; Takayama, M.; Ezura, H. (2020). Challenges and prospects of new plant breeding techniques for GABA improvement in crops: tomato as an example. Frontiers in Plant Science. 11:1-16. https://doi.org/10.3389/fpls.2020.577980S1161

Anthraquinones from Morinda elliptica

Phytochemical studies on roots of Morinda elliptica have resulted in the isolation of a new anthraquinone, 2-formyl-1-hydroxyanthraquinone, and 10 known anthraquinones. The structures of the anthraquinones were established based on spectral studies

Suppression of γ-Aminobutyric Acid (GABA) Transaminases Induces Prominent GABA Accumulation, Dwarfism and Infertility in the Tomato (Solanum lycopersicum L.)

Tomatoes accumulate γ-aminobutyric acid (GABA) at high levels in the immature fruits. GABA is rapidly converted to succinate during fruit ripening through the activities of GABA transaminase (GABA-T) and succinate semialdehyde dehydrogenase (SSADH). Although three genes encoding GABA-T and both pyruvate- and α-ketoglutarate-dependent GABA-T activities have been detected in tomato fruits, the mechanism underlying the GABA-T-mediated conversion of GABA has not been fully understood. In this work, we conducted loss-of-function analyses utilizing RNA interference (RNAi) transgenic plants with suppressed pyruvate- and glyoxylate-dependent GABA-T gene expression to clarify which GABA-T isoforms are essential for its function. The RNAi plants with suppressed SlGABA-T gene expression, particularly SlGABA-T1, showed severe dwarfism and infertility. SlGABA-T1 expression was inversely associated with GABA levels in the fruit at the red ripe stage. The GABA contents in 35S::SlGABA-T1RNAi lines were 1.3–2.0 times and 6.8–9.2 times higher in mature green and red ripe fruits, respectively, than the contents in wild-type fruits. In addition, SlGABA-T1 expression was strongly suppressed in the GABA-accumulating lines. These results indicate that pyruvate- and glyoxylate-dependent GABA-T is the essential isoform for GABA metabolism in tomato plants and that GABA-T1 primarily contributes to GABA reduction in the ripening fruits

Artelastokromen Suatu Diprenilpiranoflavon dan B-Resorsilaldehid dari Kayu Batang Artocarpus Lanceifolius

Abstrak. Dua senyawa, yaitu artelactokromen (1), suatu diprenil piranoflavon, dan B-resorsilaldehid (2) telah ditemukan untuk pertama kalinya pada kayu batang tumbuhan Artocarpus lanceifolius Roxb. (Moraceae), suatu tumbuhan langka yang endemic untuk Indonesia dan dikenal dengan nama Keledang. Struktur molekul kedua senyawa tersebut telah ditetapkan berdasarkan data fisika dan spektroskopi (MS, 1H dan 13C NMR). Baik artelastokromen (1) maupun B-resorsilaldehid (2) tidak terlalu toksik terhadap nauplii udang Artemia salina Leach., masing-masing dengan LC50 298,2 dan 79,7 ug/mL. Artelastochromene a Diprenylphyranoflavone and Î’-Resorcylaldehyde from the Wood Trunk of Artocarpus LanceifoliusAbstract. Two phenolic constituent, namely artelastochromene (1), a diprenyl pyranoflavone, and β-resorcylaldehyde (2) had been isolated from the wood trunk of Artocarpus lanceifolius Roxb. (Moraceae), an endemic species of Indonesia, locally known as Keledang. The structures of both compounds were elucidated based on physical and spectroscopic data (MS, 1H and 13C NMR). Both artelastochromene (1) and β-resorcylaldehyde (2) showed very slight toxic effect against shrimp nauplii Artemia salina Leach., LC50 298,2 and 79,7 μg/mL, respectively

Artoindonesianin-E suatu senyawa baru turunan flavanon dari tumbuhan Artocarpus Champeden

Sari. Suatu senyawabaru turunan flavanon, yakni 5,7-dihidroksi-2',4',6'-trimetoksiflavanon yang diberi nama artoindonesianin-E(1 ), telah ditemukan untuk pertama kalinya bersama-samad engan artokarpin (2) dan heteroflavanon-A (3) pada ekstrak benzena kulit batang tumbuhan Artocarpus champeden Spreng (Moraceae), suatu tumbuhan yang endemik untuk Indonesia, serta dikenal dengan narna Cempedak. Struktur molekul senyawa tersebut telah ditetapkan berdasarkan data fisika dan spekroskopi (MS, 1H dan 13C NMR).Artoindonesianin-E a New Flavanone Derivative from Artocarpus ChampedenAbstract. A new flavanone derivative, 5,7-dihydroxy-2',4',6'-trimethoxyflavanone named artoindonesianin-E (1) had been isolated for the first time, together with artocarpin (2) and heteroflavanone-A (3) from benzene extract of the tree bark of Artocarpus champeden Spreng. (Moraceae), a species endemic to Indonesia and locally known as Cempedak. The structure of this compound was elucidated based on physical and spectroscopic data (MS, 1H and 13C NMR)

Efficient increase of ɣ-aminobutyric acid (GABA) content in tomato fruits by targeted mutagenesis

γ-Aminobutyric acid (GABA) is a non-proteinogenic amino acid that has hypotensive effects. Tomato (Solanum lycopersicum L.) is among the most widely cultivated and consumed vegetables in the world and contains higher levels of GABA than other major crops. Increasing these levels can further enhance the blood pressure-lowering function of tomato fruit. Glutamate decarboxylase (GAD) is a key enzyme in GABA biosynthesis; it has a C-terminal autoinhibitory domain that regulates enzymatic function, and deleting this domain increases GAD activity. The tomato genome has five GAD genes (SlGAD1–5), of which two (SlGAD2 and SlGAD3) are expressed during tomato fruit development. To increase GABA content in tomato, we deleted the autoinhibitory domain of SlGAD2 and SlGAD3 using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas)9 technology. Introducing a stop codon immediately before the autoinhibitory domain increased GABA accumulation by 7 to 15 fold while having variable effects on plant and fruit size and yield. This is the first study describing the application of the CRISPR/Cas9 system to increase GABA content in tomato fruits. Our findings provide a basis for the improvement of other types of crop by CRISPR/Cas9-based genetic modification

Tomato Glutamate Decarboxylase Genes SlGAD2 and SlGAD3 Play Key Roles in Regulating γ-Aminobutyric Acid Levels in Tomato (Solanum lycopersicum)

Tomato (Solanum lycopersicum) can accumulate relatively high levels of γ-aminobutyric acid (GABA) during fruit development. However, the molecular mechanism underlying GABA accumulation and its physiological function in tomato fruits remain elusive. We previously identified three tomato genes (SlGAD1, SlGAD2 and SlGAD3) encoding glutamate decarboxylase (GAD), likely the key enzyme for GABA biosynthesis in tomato fruits. In this study, we generated transgenic tomato plants in which each SlGAD was suppressed and those in which all three SlGADs were simultaneously suppressed. A significant decrease in GABA levels, i.e. 50–81% compared with wild-type (WT) levels, was observed in mature green (MG) fruits of the SlGAD2-suppressed lines, while a more drastic reduction (up to <10% of WT levels) was observed in the SlGAD3- and triple SlGAD-suppressed lines. These findings suggest that both SlGAD2 and SlGAD3 expression are crucial for GABA biosynthesis in tomato fruits. The importance of SlGAD3 expression was also confirmed by generating transgenic tomato plants that over-expressed SlGAD3. The MG and red fruits of the over-expressing transgenic lines contained higher levels of GABA (2.7- to 5.2-fold) than those of the WT. We also determined that strong down-regulation of the SlGADs had little effect on overall plant growth, fruit development or primary fruit metabolism under normal growth conditions

LRP1 Functions as an Atheroprotective Integrator of TGFβ and PDGF Signals in the Vascular Wall: Implications for Marfan Syndrome

BACKGROUND: The multifunctional receptor LRP1 controls expression, activity and trafficking of the PDGF receptor-β in vascular smooth muscle cells (VSMC). LRP1 is also a receptor for TGFβ1 and is required for TGFβ mediated inhibition of cell proliferation. METHODS AND PRINCIPAL FINDINGS: We show that loss of LRP1 in VSMC (smLRP(−)) in vivo results in a Marfan-like syndrome with nuclear accumulation of phosphorylated Smad2/3, disruption of elastic layers, tortuous aorta, and increased expression of the TGFβ target genes thrombospondin-1 (TSP1) and PDGFRβ in the vascular wall. Treatment of smLRP1(−) animals with the PPARγ agonist rosiglitazone abolished nuclear pSmad accumulation, reversed the Marfan-like phenotype, and markedly reduced smooth muscle proliferation, fibrosis and atherosclerosis independent of plasma cholesterol levels. CONCLUSIONS AND SIGNIFICANCE: Our findings are consistent with an activation of TGFβ signals in the LRP1-deficient vascular wall. LRP1 may function as an integrator of proliferative and anti-proliferative signals that control physiological mechanisms common to the pathogenesis of Marfan syndrome and atherosclerosis, and this is essential for maintaining vascular wall integrity

The development of writing in Japanese and English of JHL speakers and the dynamics of bilingual learning

This study was designed to examine the development of writing proficiency in Japanese and English of JHL (Japanese as a Heritage Language) speakers, and investigate the relationship between acquiring writing skills in the two languages from the viewpoint of bilingualism. Twenty-one adults participated. Data were collected via questionnaires to obtain the participants' language background and writing samples in Japanese and English using one essay topic. The essays were analyzed quantitatively. The results confirmed Cummins' interdependence hypothesis for writing in both languages if the writers were in the additive state. Although a variety of significant correlation coefficients were observed between the categories of WE (Writing Expertise; content and organization) in Japanese and those of LP (Language Proficiency; vocabulary, grammar, and mechanics) in English, no notable relationships were seen between the same categories. The interdependence hypothesis in non-cognate languages such as Japanese and English does not work solely on the basis of surface individual linguistic knowledge