low , ▁ 2 0 0 7 ). ▁ ▁Germ ination ▁Sp ores ▁can ▁remain ▁d orm ant ▁for ▁extended ▁time ▁periods ▁and ▁possess ▁a ▁remarkable ▁resistance ▁to ▁environmental ▁dam ages , ▁such ▁as ▁heat , ▁radiation , ▁to xic ▁chemical s , ▁and ▁p H ▁extrem es . ▁Under ▁favor able ▁environmental ▁conditions , ▁the ▁sp ore ▁breaks ▁d orm ancy ▁and ▁rest arts ▁growth ▁in ▁a ▁process ▁called ▁sp ore ▁germ ination ▁and ▁out g row th ▁( Fig . ▁ 3 ). ▁The ▁germ ination ▁process ▁occurs ▁in ▁the ▁following ▁three ▁stages : ▁Stage ▁I : ▁Activ ation , ▁defined ▁as ▁the ▁init iation ▁or ▁trigger ing ▁process ▁in ▁response ▁to ▁nut r itional ▁re pl en ishment ▁that ▁occurs ▁when ▁the ▁germ in ating ▁mole cules , ▁including ▁low - m ole cular - weight ▁am ino ▁ac ids , ▁sug ars , ▁and ▁pur ine ▁nucle os ides , ▁are ▁sens ed ▁by ▁germ ination ▁re cept ors ▁( GR s ) ▁located ▁in ▁the ▁inner ▁memb rane ▁of ▁the ▁sp ore . ▁These ▁re cept ors ▁include , ▁ger A , ▁ger B , ▁or ▁ger K , ▁and ▁the ▁germ in ating ▁mole cules ▁bind ▁these ▁re cept ors . ▁l - al an ine ▁acts ▁through ▁the ▁ger A ▁re ceptor , ▁and ▁a ▁mixture ▁of ▁l - as par agine , ▁f ruct ose , ▁gl uc ose ▁and ▁K Cl ▁( AG F K ) ▁bind ▁the ▁ger B ▁and ▁ger K ▁re