[陽明大一普通生物] plant biology part1

植物的基本介紹

1.      meristem：

a.       primary meristem(apical)：SAM，RAM

b.      secondary meristem(lateral)：cabium

c.       meristem產生三種主要的細胞，在進行分化

(1)   ground meristem----ground tissue

(2)   protoderm----dermal tissue

(3)   procambium----vascular tissue

d.      植物生長的原則：apical-basal polarity，radial symmetry

2.      Plant cell expansion：酸性生長假說

a.       expand by taking up water

b.      proton pump increase cell wall acidity-----activate expansion protein (expansin)----upzip cross-linking polysaccharide----cell absorb water ----exert pressure on the wall----cell expansion

c.       direction of cell expansion：controlled by microfibrils and microtubule ，decided during late interphase ---- microtubule will form a preprophase ring

 (註：interphase  prophase  metaphase  anaphase  telophase )

3.      Cell differentiation

a.       location：

root hair：epidermal cells that border one cortical cell produce GLABRA-2----no hair root

b.      chemical：plant hormone

4.      表皮特化的構造：

a.       guard cell：導因於細胞分裂的asymmetry

b.      trichome：主要的功能為保護植物體，並提供降溫，減少蒸散的功能。但需消耗較多的能量以製造trichome，當trichome initiator超過閾值後，就會引發細胞產生trichome