Initiator-independent and initiator-dependent rubber biosynthesis in Ficus elastica

Initiation of rubber biosynthesis: In vitro comparisons of benzophenone-modified diphosphate analogues in three rubber-producing species

“…In fact, F. elastica rubber transferase was 4-20 times lower in substrate affinity compared to H. brasiliensis. Similar results had been observed previously (Espy et al, 2006). FPP initiated rubber synthesis more efficiently than did GPP or DMAPP in all three rubber-producing species, as indicated by a higher rate of IPP incorporation (Fig.…”

Natural rubber biosynthesis in plants, the rubber transferase complex, and metabolic engineering progress and prospects

“…RT‐ases form a distinct subgroup of the cis ‐prenyltransferase (CPT) family (Akhtar et al, 2013; Asawatreratanakul et al ., ; Cornish et al ., ; Epping et al ., ; Espy et al ., ; Hemmi et al ., ; Kharel and Koyama, ; Oh et al ., ; Schmidt et al ., ; Yamashita et al ., ). RT‐ases have low substrate affinity for IPP, which prevents rubber biosynthesis from causing critical IPP deficits—rubber can only be made when IPP is in excess of cellular metabolic requirements (Cornish, ,b; da Costa et al ., , ).…”

“…). In general, two mechanisms have been proposed for NR biosynthesis: (i) the de novo formation of NR via sequential cis ‐1,4‐condensation of IPP, via a carbocationic reaction (Puskas et al ., ), onto short‐chain allylic pyrophosphates as priming substrates and (ii) addition of IPP at the α‐terminus of partially polymerized rubber molecules or polyprenyl pyrophosphates (Cornish, ,b; Espy et al ., ; Rojruthai et al ., ; Tong et al ., ; Wallrapp et al ., ; Yamashita et al ., ; Figure ). It should be noted that the active end of an elongating rubber molecule is an APP moiety.…”

“…Despite the emerging strong interest and investment in alternative rubber crops, and a good understanding of NR enzymology (Archer and Audley, ; Cornish, ,b; Cornish et al . ; Cornish and Scott, ; Cornish and Xie, ; da Costa et al ., , ; Espy et al ., ; Kang et al ., ,b), our current understanding of the protein chemistry and the molecular mechanisms involved in rubber biosynthesis is far less complete and has not been recently reviewed. Therefore, here we review the recent biotechnological/metabolic pathway engineering advances made towards improving natural rubber yield and quality (specifically high molecular weight NR) in rubber plants.…”

A biochemical and ultrastructural analysis of rubber biosynthesis in Parthenium argentatum Gray in the Chihuahuan Desert

“…This allylic-PP initiated RT reaction is an example of the de novo synthesis of rubber polymer. Espy et al (2006) reported a chain elongation of rubber-PP in Ficus catalyzed by RT. Rojruthai et al (2010) reported an RTcatalyzed synthesis of high molecular weight rubber in Hevea small rubber particles by an elongation of pre-existing chains of rubber-PP.…”