Shan Fuxin, Zhang Rui, Zhang Jin, Wang Chang, Lyu Xiaochen, Xin Tianyu, Yan Chao, Dong Shoukun, Ma Chunmei, Gong Zhenping
College of Agriculture, Northeast Agricultural University, Harbin 150030, China.
College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming 650201, China.
Plants (Basel). 2021 Aug 23;10(8):1737. doi: 10.3390/plants10081737.
Excessive plant height is an important factor that can lead to lodging, which is closely related to soybean yield. Gibberellins are widely used as plant growth regulators in agricultural production. Gibberellic acid (GA), one of the most effective active gibberellins, has been used to regulate plant height and increase yields. The mechanism through which GA regulates internode elongation has been extensively investigated. In 2019 and 2020, we applied GA to the stems, leaves, and roots of two soybean cultivars, Heinong 48 (a high-stalk cultivar) and Henong 60 (a dwarf cultivar), and GA was also applied to plants whose apical meristem was removed or to girded plants to compare the internode length and stem GA content of soybean plants under different treatments. These results suggested that the application of GA to the stems, leaves, and roots of soybean increased the internode length and GA content in the stems. Application of GA decreased the proportion of the pith in the soybean stems and primary xylem while increasing the proportion of secondary xylem. The apical meristem is an important site of GA synthesis in soybean stems and is involved in the regulation of stem elongation. GA was shown to be transported acropetally through the xylem and laterally between the xylem and phloem in soybean stems. We conclude that the GA level in stems is an important factor affecting internode elongation.
植株过高是导致倒伏的一个重要因素，而倒伏与大豆产量密切相关。赤霉素在农业生产中被广泛用作植物生长调节剂。赤霉酸（GA）是最有效的活性赤霉素之一，已被用于调控植株高度并提高产量。GA调控节间伸长的机制已得到广泛研究。在2019年和2020年，我们将GA施用于两个大豆品种（高秆品种黑农48和矮秆品种黑农60）的茎、叶和根上，还将GA施用于去除顶端分生组织的植株或环割植株上，以比较不同处理下大豆植株的节间长度和茎中GA含量。这些结果表明，将GA施用于大豆的茎、叶和根上会增加节间长度和茎中的GA含量。施用GA会降低大豆茎中髓和初生木质部的比例，同时增加次生木质部的比例。顶端分生组织是大豆茎中GA合成的重要部位，参与茎伸长的调控。GA在大豆茎中通过木质部向上运输，并在木质部和韧皮部之间横向运输。我们得出结论，茎中的GA水平是影响节间伸长的一个重要因素。
