▁for ests ▁may ▁depend ▁significantly ▁more ▁on ▁their ▁fung al ▁partner ▁for ▁carbon , ▁varying ▁within ▁and ▁between ▁species , ▁demonstr ating ▁the ▁variable ▁and ▁re active ▁nature ▁of ▁these ▁interaction . ▁ ▁N ut ri ent ▁transfer ▁interfaces ▁and ▁mechan isms ▁ ▁At ▁in fection ▁of ▁an ▁orch id ▁by ▁a ▁my cor rh iz al ▁fung us ▁both ▁partners ▁are ▁alter ed ▁consider ably ▁to ▁allow ▁for ▁nut ri ent ▁transfer ▁and ▁sym b ios is . ▁N ut ri ent ▁transfer ▁mechan isms ▁and ▁the ▁sym bi otic ▁my cor rh iz al ▁pel ot on ▁org ans ▁start ▁to ▁appear ▁only ▁shortly ▁after ▁in fection ▁around ▁ 2 0 – 3 6 ▁hours ▁after ▁initial ▁contact . ▁There ▁is ▁significant ▁gen etic ▁up reg ulation ▁and ▁down reg ulation ▁of ▁many ▁different ▁gen es ▁to ▁facil itate ▁the ▁creation ▁of ▁the ▁sym bi otic ▁organ , ▁and ▁the ▁path ways ▁with ▁which ▁nut ri ents ▁travel . ▁As ▁the ▁fung us ▁enters ▁the ▁par en chy ma ▁cells ▁of ▁the ▁orch id ▁the ▁pl asma ▁memb rane ▁inv agin ates ▁to ▁facil itate ▁fung al ▁in fection ▁and ▁growth . ▁This ▁newly ▁inv agin ated ▁pl asma ▁memb rane ▁surr ounds ▁the ▁growing ▁pel ot ons ▁and ▁creates ▁a ▁huge ▁surface ▁area ▁from ▁which ▁nut ri ents ▁can ▁be ▁ex changed . ▁The ▁pel ot ons ▁of ▁orch id ▁my cor rh iza ▁are ▁intens ely ▁co iled ▁dense ▁fung al ▁hy pha e ▁that ▁are ▁often ▁more ▁extensive