02357nas a2200253   4500008004100000245011500041210006900156260000800225300000900233490000700242520149500249100002701744700002301771700001801794700002001812700002001832700002601852700001601878700002001894700002401914700002001938700001901958856012601977       2023                        eng d00aBAHD-type acyltransferase concludes the biosynthetic pathway of non-bitter glycoalkaloids in ripe tomato fruit0 aBAHDtype acyltransferase concludes the biosynthetic pathway of n  cJUL  a45400 v143 a<p>
	During tomato fruit ripening, bitter and toxic steroidal glycoalkaloids (SGAs) are converted to nonbitter and less toxic forms, but proposed acylating enzyme in pathway remain unknown. Here, authors report BAHD-type acyltransferase that catalyze acylation step in biosynthesis of non-bitter SGAs in tomato. Tomato is the highest value fruit and vegetable crop worldwide, yet produces &amp; alpha;-tomatine, a renowned toxic and bitter-tasting anti-nutritional steroidal glycoalkaloid (SGA) involved in plant defense. A suite of modifications during tomato fruit maturation and ripening converts &amp; alpha;-tomatine to the non-bitter and less toxic Esculeoside A. This important metabolic shift prevents bitterness and toxicity in ripe tomato fruit. While the enzymes catalyzing glycosylation and hydroxylation reactions in the Esculeoside A pathway have been resolved, the proposed acetylating step remains, to date, elusive. Here, we discovered that GAME36 (GLYCOALKALOID METABOLISM36), a BAHD-type acyltransferase catalyzes SGA-acetylation in cultivated and wild tomatoes. This finding completes the elucidation of the core Esculeoside A biosynthetic pathway in ripe tomato, allowing reconstitution of Esculeoside A production in heterologous microbial and plant hosts. The involvement of GAME36 in bitter SGA detoxification pathway points to a key role in the evolution of sweet-tasting tomato as well as in the domestication and breeding of modern cultivated tomato fruit.</p>
1 aSonawane, Prashant, D.1 aGharat, Sachin, A.1 aJozwiak, Adam1 aBarbole, Ranjit1 aHeinicke, Sarah1 aAlmekias-Siegl, Efrat1 aMeir, Sagit1 aRogachev, Ilana1 aO'Connor, Sarah, E.1 aGiri, Ashok, P.1 aAharoni, Asaph  uhttp://library.ncl.res.in/content/bahd-type-acyltransferase-concludes-biosynthetic-pathway-non-bitter-glycoalkaloids-ripe02698nas a2200325   4500008004100000022001400041245006800055210006800123260000900191300001400200490000700214520169800221653001801919653002501937653002401962653001201986653002801998653002902026100002102055700002602076700001902102700002102121700002002142700002002162700002002182700002002202700002402222700002702246856009902273       2024                        eng d  a1674-205200aSteroidal scaffold decorations in Solanum alkaloid biosynthesis0 aSteroidal scaffold decorations in Solanum alkaloid biosynthesis  cAUG   a1236-12540 v173 a<p>
	Steroidal glycoalkaloids (SGAs) are specialized metabolites produced by hundreds of Solanum species, including important vegetable crops such as tomato, potato, and eggplant. Although it has been known that SGAs play important roles in defense in plants and ``anti-nutritional''effects (e.g., toxicity and bitterness) to humans, many of these molecules have documented anti-cancer, anti-microbial, antiinflammatory, anti-viral, and anti-pyretic activities. Among these, a-solasonine and a-solamargine isolated from black nightshade (Solanum nigrum) are reported to have potent anti-tumor, anti-proliferative, and anti-inflammatory activities. Notably, a-solasonine and a-solamargine, along with the core steroidal aglycone solasodine, are the most widespread SGAs produced among the Solanum plants. However, it is still unknown how plants synthesize these bioactive steroidal molecules. Through comparative metabolomictranscriptome-guided approach, biosynthetic logic, combinatorial expression in Nicotiana benthamiana, and functional recombinant enzyme assays, here we report the discovery of 12 enzymes from S. nigrum that converts the starting cholesterol precursor to solasodine aglycone, and the downstream a-solasonine, a-solamargine, and malonyl-solamargine SGA products. We further identified six enzymes from cultivated eggplant that catalyze the production of a-solasonine, a-solamargine, and malonyl-solamargine SGAs from solasodine aglycone via glycosylation and atypical malonylation decorations. Our work provides the gene tool box and platform for engineering the production of high-value, steroidal bioactive molecules in heterologous hosts using synthetic biology.</p>
10aa-solamargine10aBiosynthetic pathway10amalonyl-solamargine10aSolanum10aSpecialized metabolites10asteroidal glycoalkaloids1 aLucier, Rosalind1 aKamileen, Mohamed, O.1 aNakamura, Yoko1 aSerediuk, Sofiia1 aBarbole, Ranjit1 aWurlitzer, Jens1 aKunert, Maritta1 aHeinicke, Sarah1 aO'Connor, Sarah, E.1 aSonawane, Prashant, D.  uhttp://library.ncl.res.in/content/steroidal-scaffold-decorations-solanum-alkaloid-biosynthesis