低温锻炼( Cold hardening):预先以适当、 安全的低温给予植物一定时间的处理。 提高植物耐寒性的有效措施 100 o unacclimated cold acclimated 80 60 40 20 6 9-10 temperature(c) Leakage of electrolytes from mature Arabidopsis leaves before and after acclimation at 4 C for 7d
三、低温锻炼（Cold hardening）：预先以适当、 安全的低温给予植物一定时间的处理。 提高植物耐寒性的有效措施 • Leakage of electrolytes from mature Arabidopsis leaves before and after acclimation at 4°C for 7d
Freezing-sensitive Freezing-tolerant response response Osmotic loss During freezing of water occurs during freezing and stress, changes in area decreases unacclimated cells In acclimated cells, plasma membrane membrane material membrane material is ost by endocytotic retained as attached ciculation xocytotic extrusions morphology determine death or survive of the cell and upon thawing and upon thawing these allow for lysis of the plasma reexpansion of the cell menbrane
• During freezing stress, changes in plasma membrane morphology determine death or survive of the cell
Cold acclimation allows plants to survive freezing kept at-5 C for 4d, and then transferred to growth conditions at 23 C for 10d
Cold acclimation allows plants to survive freezing • The Arabidopsis plants on the right were incubated at 4 °C for 4d to acclimate the plants, after which both pots were kept at -5 °C for 4d, and then transferred to growth conditions at 23 °C for 10d
第二节高温胁迫和植物抗热性
第二节 高温胁迫和植物抗热性
高温引起的生理反应: 细胞结构的损伤(细胞器和细胞骨架); 膜功能受损 基因表达改变 蛋白质的合成改变(正常蛋白合成受阻,诱导HSPs合成) 主要的热激蛋白及其功能(数字:MW HSP family Probable function HSP110 Unknown HSP90 Protecting receptor proteins HSP70 ATP-dependent protein assembly or disassembly reactions; preventing proteins from denaturation HSP60 Molecular chaperone, directing the proper assembly of multi-subunit proteins LMW HSPs Function largely unknown (17-28KDa) Ubiquitin An 8 kDa protein involved in targeting other proteins for proteolytic degration
高温引起的生理反应： 细胞结构的损伤（细胞器和细胞骨架）； 膜功能受损 基因表达改变 蛋白质的合成改变（正常蛋白合成受阻，诱导HSPs合成） • 主要的热激蛋白及其功能（数字：MW) HSP family Probable function HSP110 Unknown HSP90 Protecting receptor proteins HSP70 ATP-dependent protein assembly or disassembly reactions; preventing proteins from denaturation HSP60 Molecular chaperone, directing the proper assembly of multi-subunit proteins LMW HSPs Function largely unknown (17-28kDa) Ubiquitin An 8 kDa protein involved in targeting other proteins for proteolytic degration