Authors: Miyazawa, S.-I.; Terashima, I.

Source: Plant, Cell & Environment, Volume 24, Number 3, March 2001 , pp. 279-291(13)

Publisher: Wiley-Blackwell

Abstract:

Changes in net photosynthetic rate on a leaf area basis and anatomical properties during leaf development were studied in an evergreen broad-leaved tree, Castanopsis sieboldii and an annual herb, Phaseolus vulgaris. In C. sieboldii, surface area of mesophyll cells facing the intercellular air spaces on a leaf area basis (S_mes) was already considerable at the time of full leaf area expansion (FLE). However, surface area of chloroplasts facing the intercellular air spaces on a leaf area basis (S_c), and chlorophyll and Rubisco contents on a leaf area basis increased to attain their maximal values 15-40 d after FLE. In contrast, in P. vulgaris, chloroplast number on a leaf area basis, S_c and S_mes at 10 d before FLE were two to three times greater than the steady-state levels attained at around FLE. In C. sieboldii, the internal CO₂ transfer conductance (g_i) slightly increased for 10 d after FLE but then decreased toward the later stages. Limitation of photosynthesis by g_i was only about 10% at FLE, but then increased to about 30% at around 40 d after FLE. The large limitation after FLE by g_i was probably due to the decrease in CO₂ concentration in the chloroplast caused by the increases in thickness of mesophyll cell walls and in Rubisco content per chloroplast surface area. These results clearly showed that: (1) in C. sieboldii, chloroplast development proceeded more slowly than mesophyll cell expansion and continued well after FLE, whereas in P. vulgaris these processes proceeded synchronously and were completed by FLE; (2) after FLE, photosynthesis in leaves of C. sieboldii was markedly limited by g_i. From these results, it is suggested that, in the evergreen broad-leaved trees, mechanical protection of mesophyll cells has priority over the efficient CO₂ transfer and quick construction of the chloroplasts.

Keywords: chloroplast development; evergreen broad-leaved tree; internal CO2 transfer conductance; leaf age; leaf anatomy; leaf development; photosynthesis

Document Type: Research article

DOI: http://dx.doi.org/10.1046/j.1365-3040.2001.00682.x

Affiliations: 1: Department of Biology, Graduate School of Science, Osaka University, 1-16 Machikaneyama-Cho, Toyonaka, Osaka, 560-0043 Japan

Publication date: 2001-03-01

Related content

• In this: publication
• By this: publisher
• In this Subject: Botany
• By this author: Miyazawa, S.-I. ;  Terashima, I.

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers