Root-zone temperature effects on photosynthesis, 14C-photoassimilate partitioning and growth of temperate lettuce (Lactuca sativa cv. 'Panama') in the tropics

Title:

Root-zone temperature effects on photosynthesis, 14C-photoassimilate partitioning and growth of temperate lettuce (Lactuca sativa cv. 'Panama') in the tropics

Creator:

He, J., Tan, L. P., and Lee, S. K.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:e5efd996-ad00-42b2-8755-71b158e0dfdf
uuid:e5efd996-ad00-42b2-8755-71b158e0dfdf
issn:0300-3604
doi:10.1007/s11099-009-0015-6

Subject:

14C-photoassimilate, carbohydrate, lettuce, photosynthetic CO2 assimilation, root morphology, and root-zone temperature

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

The effect of root growth temperature on maximal photosynthetic CO2 assimilation (Pmax), carbohydrate content, 14C-photoassimilate partitioning, growth, and root morphology of lettuce was studied after transfer of the root system from cool root-zone temperature (C-RZT) of 20 °C to hot ambient-RZT (A-RZT) and vice versa. Four days after RZT transfer, Pmax and leaf total soluble sugar content were highest and lowest, respectively, in C-RZT and A-RZT plants. Pmax and total leaf soluble sugar content were much lower in plants transferred from C-to A-RZT (C→A-RZT) than in C-RZT plants. However, these two parameters were much higher in plants transferred from A-to C-RZT (A→C-RZT) than in A-RZT plants. A-RZT and C→A-RZT plants had higher root total soluble sugar content than A→C-RZT and C-RZT plants. Leaf total insoluble sugar content was similar in leaves of all plants while it was the highest in the roots of C-RZT plants. Developing leaves of C-RZT plants had higher 14C-photoassimilate content than A-RZT plants. The A→C-RZT plants also had higher 14C-photoassimilate content in their developing leaves than A-RZT plants. However, more 14C-photoassimilates were translocated to the roots of A-RZT and C→A-RZT plants, but they were mainly used for root thickening than for its elongation. Increases in leaf area, shoot and root fresh mass were slower in C→A-RZT than in C-RZT plants. Conversely, A→C-RZT plants had higher increases in these parameters than A-RZT plants. Lower root/shoot ratio (R/S) in C-RZT than in A-RZT plants confirmed that more photoassimilates were channelled to the shoots than to the roots of C-RZT plants. Roots of C-RZT plants had greater total length with a greater number of tips and surface area, and smaller average diameter as compared to A-RZT plants. In C→A-RZT plants, there was root thickening but the increases in its length, tip number and surface area decreased. The reverse was observed for A→C-RZT plants. These results further supported the idea that newly fixed photoassimilates contributed more to root thickening than to root elongation in A-RZT and C→A-RZT plants. and J. He, L. P. Tan, S. K. Lee.

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

95-103

Source:

Photosynthetica | 2009 Volume:47 | Number:1

Harvested from:

CDK

Metadata only:

false