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Gibberellins and auxin regulate soybean hypocotyl elongation under low light and high-temperature interaction |
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| Authors: | George Bawa Lingyang Feng Guopeng Chen Hong Chen Yun Hu Tian Pu Yajiao Cheng Jianyi Shi Te Xiao Wenguan Zhou Taiwen Yong Xin Sun Feng Yang Wenyu Yang Xiaochun Wang |
| Affiliation: | 1. Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, 611130 China;2. Sichuan Engineering Research Center for Crop Strip Intercropping System, Sichuan Agricultural University, Chengdu, 611130 China Key Laboratory of Crop Ecophysiology and Farming System in Southwest China (Ministry of Agriculture), Sichuan Agricultural University, Chengdu, 611130 China College of Agronomy, Sichuan Agricultural University, Chengdu, 611130 China |
| Abstract: | Soybean is an important oilseed crop grown globally. However, two examples of environmental stresses that drastically regulate soybean growth are low light and high-temperature. Emerging evidence suggests a possible interconnection between these two environmental stimuli. Low light and high-temperature as individual factors have been reported to regulate plant hypocotyl elongation. However, their interactive signal effect on soybean growth and development remains largely unclear. Here, we report that gibberellins (GAs) and auxin are required for soybean hypocotyl elongation under low light and high-temperature interaction. Our analysis indicated that low light and high-temperature interaction enhanced the regulation of soybean hypocotyl elongation and that the endogenous GA3, GA7, indole-3-acetic acid (IAA), and indole-3-pyruvate (IPA) contents significantly increased. Again, analysis of the effect of exogenous phytohormones and biosynthesis inhibitors treatments showed that exogenous GA, IAA, and paclobutrazol (PAC), 2, 3, 5,-triiodobenzoic acid (TIBA) treatments significantly regulated soybean seedlings growth under low light and high-temperature interaction. Further qRT-PCR analysis showed that the expression level of GA biosynthesis pathway genes (GmGA3ox1, GmGA3ox2 and GmGA3) and auxin biosynthesis pathway genes (GmYUCCA3, GmYUCCA5 and GmYUCCA7) significantly increased under (i) low light and high-temperature interaction and (ii) exogenous GA and IAA treatments. Altogether, these observations support the hypothesis that gibberellins and auxin regulate soybean hypocotyl elongation under low light and high-temperature stress interaction. |
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