The sng2 mutant of Arabidopsis is defective in the gene encoding the serine carboxypeptidase-like protein sinapoylglucose : choline sinapoyltransferase

Shirley, AM McMichael, CM Chapple, C

Am. Shirley et al., The sng2 mutant of Arabidopsis is defective in the gene encoding the serine carboxypeptidase-like protein sinapoylglucose : choline sinapoyltransferase, PLANT J, 28(1), 2001, pp. 83-94

35

INGLESE

Article

Plant Sciences","Animal & Plant Sciences

PLANT JOURNAL

0960-7412 → ACNP

28

1

2001

83 - 94

ISI

0960-7412(200110)28:1<83:TSMOAI>2.0.ZU;2-6

Serine carboxypeptidase-like (SCPL) proteins have traditionally been assign ed roles in the hydrolytic processing of proteins; however, several SCPL pr oteins have recently been identified as catalysts in transacylation reactio ns of plant secondary metabolism. The novel functions of these enzymes sugg est a catalytic diversity for plant SCPL proteins that extends beyond simpl e hydrolysis reactions. Characterization of the Arabidopsis sng2 (sinapoylg lucose accumulator 2) mutant has identified another SCPL protein involved i n plant secondary metabolism. The sng2 mutant was isolated by screening see d extracts for altered levels of sinapate esters, a group of phenylpropanoi d compounds found in Arabidopsis and some other members of the Brassicaceae . Homozygous sng2 seeds accumulate sinapoylglucose instead of sinapoylcholi ne, and have increased levels of choline and decreased activity of the enzy me sinapoylglucose:choline sinapoyltransferase (SCT). Cloning of the SNG2 g ene by a combination of map-based and candidate gene approaches demonstrate s that SCT is another member of the growing class of SCPL acyltransferases involved in plant secondary metabolism.