Manipulation of lignin metabolism by plant densities and its relationship with lodging resistance in wheat.
Increasing plant density is one of the most efficient ways of increasing wheat (Triticum aestivum L.) grain production. However, overly dense plant populations have an increased risk of lodging. We examined lignin deposition during wheat stem development and the regulatory effects of plant density using the wheat cultivars shannong23 and weimai8. Plants were cultivated at densities of 75, 225 and 375 plants per m2during two growing seasons. Our results showed that decreasing plant density enhanced culm quality, as revealed by increased culm diameter, wall thickness and dry weight per unit length, and improved the structure of sclerenchyma and vascular bundles by increasing lignification. In addition, more lignins were deposited in the secondary cell walls, resulting in strong lodging resistance. The guaiacyl unit was the major component of lignin and there was a higher content of the syringyl unit than that of the hydroxybenzyl unit. Furthermore, we hypothesised that the syringyl unit may correlate with stem stiffness. We describe here, to the best of our knowledge, the systematic study of the mechanism involved in the regulation of stem breaking strength by plant density, particularly the effect of plant density on lignin biosynthesis and its relationship with lodging resistance in wheat.
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Mengjing
M
Zheng
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Jin
J
Chen
Agricultural Bureau of Yanzhou District, Jining, Shandong, P. R. China.
Yuhua
Y
Shi
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Yanxia
Y
Li
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Yanping
Y
Yin
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Dongqing
D
Yang
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Yongli
Y
Luo
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Dangwei
D
Pang
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Xu
X
Xu
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Wenqian
W
Li
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Jun
J
Ni
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Yuanyuan
Y
Wang
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Zhenlin
Z
Wang
State Key Laboratory of Crop Biology, Ministry of Science and Technology, Shandong Agricultural University, Tai'an 271018, Shandong, P. R. China.
Yong
Y
Li
D050260:Carbohydrate Metabolism / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D008031:Lignin / Q000378:metabolism*; D055595:Mechanical Phenomena; D011156:Population Density; D014908:Triticum / Q000166:cytology / Q000235:genetics / Q000378:metabolism*
D008031:Lignin