Open AccessElevated CO2 alters distribution of nodal leaf area and enhances nitrogen uptake contributing to yield increase of soybean cultivars grown in Mollisols
Author(s) -
Jian Jin,
Yansheng Li,
Xiaobing Liu,
Guanghua Wang,
Caixian Tang,
Zhenhua Yu,
Xiaojuan Wang,
Stephen Herbert
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0176688
Subject(s) - cultivar , mollisol , canopy , nitrogen , soil water , agronomy , biology , yield (engineering) , sink (geography) , horticulture , photosynthesis , soil carbon , chemistry , botany , ecology , materials science , cartography , organic chemistry , metallurgy , geography
Understanding how elevated CO 2 affects dynamics of nodal leaf growth and N assimilation is crucial for the construction of high-yielding canopy via breeding and N management to cope with the future climate change. Two soybean cultivars were grown in two Mollisols differing in soil organic carbon (SOC), and exposed to ambient CO 2 (380 ppm) or elevated CO 2 (580 ppm) throughout the growth stages. Elevated CO 2 induced 4–5 more nodes, and nearly doubled the number of branches. Leaf area duration at the upper nodes from R5 to R6 was 4.3-fold greater and that on branches 2.4-fold higher under elevated CO 2 than ambient CO 2 , irrespective of cultivar and soil type. As a result, elevated CO 2 markedly increased the number of pods and seeds at these corresponding positions. The yield response to elevated CO 2 varied between the cultivars but not soils. The cultivar-specific response was likely attributed to N content per unit leaf area, the capacity of C sink in seeds and N assimilation. Elevated CO 2 did not change protein concentration in seeds of either cultivar. These results indicate that elevated CO 2 increases leaf area towards the upper nodes and branches which in turn contributes yield increase.