Transcript 식물생리학.(804)

식물생리학
육상식물
관다발식물
선태식물 (비관다발식물)
종자식물
비종자
관다발식물
차축조류
태류 각태류 선류
석송식물
양치식물
겉씨식물
속씨식물
종자식물의 기원
(약 3억 6천만 년 전)
관다발식물의 기원
(약 4억 2천만 년 전)
육상식물의 기원
(약 4억 5천 5백만 년 전)
조상 녹조류
Highlights of plant evolution (식물 진화의 하이라이트). This diagram reflects a
hypothesis about the general relationships between plant groups. The broken lines
indicate that the phylogeny of bryophytes is uncertain.
Net flow in
whole plants
Fig. 39.12a
Fig. 39.12b
Ascent of xylem sap
•transpirational pull
•flow from greater to lower
water concentration
•relies on cohesion &
adhesion of water
–cavitation breaks chain of
water molecules
Figure 35.11 Water-conducting cells of xylem
Fig. 39.11
The availability of soil water and minerals
Long-distance transport of water from roots to leaves
Phloem transport
• pressure flow
1 high sugar concentration at
“source”
2 sugar diluted with water
from xylem creating
pressure for flow
3 sugar unloaded at “sink”
where it is metabolized or
converted to starch
4 excess water flows to xylem
back to “source”
• translocation: movement
of food from “source” to
“sink(s)”
Pressure flow in a sieve tube
Some “hot” areas in plant water
and nutrient research
• Improving plant water-use efficiency
• Improving salt tolerance
• Improving nutritional value of plants (e.g.,
golden rice, increasing Fe content)
• Phytoremediation
Life on Earth
depends on
flow of energy
from sun
Fig. 10.20
Fig. 10.21
Fig. 10.22
Fig. 8.14
Fig. 9.19