Are plant biomass and growth accounted for by Leaf biochemistry of photosynthesis in rice ?

在这项研究中，我研究了光合作用的潜在能力与整个植物的生长和生物量之间的关系。虽然植物的干重大部分由光合产物组成，但许多研究表明，单位叶面积的光合速率并不一定反映整个植物的生长速率和生物量。我认为生物量和氮在整个植物水平上的形态和分配以及叶片光合作用对植物生长很重要。当然，Rubisco降低的转基因水稻植株的光合速率较低，生长和生物量也较小。然而，叶片的潜在光合作用也在整个植物生长水平上受到调节。例如，我发现CO_2富集导致叶片n含量下降。这一现象对植物在CO_2富集条件下的生长具有重要意义。这种叶片氮含量的下降不是由于叶片面积或植物生物量的相对增加造成的氮的稀释。这是整个植株氮分配变化的结果。在CO_2富集的长期生长过程中，水稻从叶片向叶鞘和根系重新分配氮素。而反义红细胞则优先将氮和生物量分配给叶片。因此，植物通过改变整个植物内氮和生物量的分配来调节叶片的光合作用。

In this study, I examined how the potential capacity of photosynthesis is related to the growth and biomass of the whole plant. Although most of the dry weight of plants consists of photosynthetic products, many studies have shown that the photosynthetic rate per unit of leaf area does not necessarily reflect the rate of the whole-plant growth and biomass. I considered that morphology and allocation of biomass and N at the level of the whole plant as well as leaf photosynthesis are important for plant growth. Of course, transgenic rice plants with decreased Rubisco showed lower rates of photosynthesis and had smaller growth and biomass. However, potential photosynthesis in a leaf was also regulated at the level of the whole-plant growth. For example, I found the decrease in leaf-N content induced by CO_2 enrichment. This phenomenon was of crucial importance for plant growth under CO_2 enrichment. This decrease in leaf-N content was not due to dilution of N caused by relative increases in the leaf area or plant biomass. This was the result of a change in N allocation of the whole plant. During long-term growth under CO_2 enrichment, rice re-allocated N away from leaf blades to leaf sheaths and roots. In contrast, the rbcS antisense rice plants preferentially allocated N and biomass into leaf blades. Thus,plants regulate photosynthesis in a leaf by changing the N and biomass allocation within the whole plant.