Targeted Phytohormone Profiling Identifies Potential Regulators of Spikelet Sterility in Rice under Combined Drought and Heat Stress
Rice cultivated under rainfed or semi-irrigated ecosystems is frequently exposed to a combination of drought and heat stress. As a sensitive crop at the reproductive stage, exposure to combined drought and heat stress will have a deleterious effect on yield. In this study, two rice cultivars with co...
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MDPI AG
2021-10-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/22/21/11690 |
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| author | Maria Vera Jesus Da Costa Venkategowda Ramegowda Sheshshayee Sreeman Karaba N. Nataraja |
| author_facet | Maria Vera Jesus Da Costa Venkategowda Ramegowda Sheshshayee Sreeman Karaba N. Nataraja |
| author_sort | Maria Vera Jesus Da Costa |
| collection | DOAJ |
| description | Rice cultivated under rainfed or semi-irrigated ecosystems is frequently exposed to a combination of drought and heat stress. As a sensitive crop at the reproductive stage, exposure to combined drought and heat stress will have a deleterious effect on yield. In this study, two rice cultivars with contrasting spikelet sterility, AVT2-5315 (low sterility) and AC35027 (high sterility), under combined stress were selected for physiological characterization and phytohormonal profiling at anthesis. Under combined stress, both cultivars did not differ in the physiological parameters such as relative water content, photosynthetic rate, light-adapted chlorophyll fluorescence and biomass, suggesting a similar source activity under stress. However, AVT2-5315 showed better yield due to better pollen and spikelet fertility than AC35027, suggesting its intrinsic tolerance ability under combined stress. Targeted profiling of 15 phytohormones from drought, heat and combined stress-treated flag leaf and spikelet tissues using LC–MS/MS showed increased accumulation of auxins (indole 3-acetic acid and indole 3-butyric acid) in flag leaves and jasmonic acid in spikelets of AVT2-5315, while there was increased accumulation of ethylene in flag leaves and methyl-jasmonate in spikelets of AC35027. Increased accumulation of these hormones correlated with key biosynthetic pathway genes. In the flag leaves, increased accumulation of auxins was correlated with increased transcript levels of <i>YUCCA-like gene 1</i> (<i>OsYUCCA1</i>) and <i>fish bone</i> (<i>OsFIB</i>), in AVT2-5315 under combined stress. In AC35027, increased ethylene content was correlated with expression of <i>1-aminocyclopropane-1-carboxylate synthase 1</i> (<i>OsASC1</i>) and <i>aminocyclopropane-1-carboxylic acid oxidase 2</i> (<i>OsACO2</i>). Similarly, in spikelets, increased accumulation of jasmonic acid in AVT2-5315 was correlated with expression of <i>allene oxide cyclase</i> (<i>OsAOC</i>) and <i>12-oxophytodienoic acid reductase 1</i> (<i>OsOPR1</i>). The mechanism of regulating spikelet sterility by these hormones needs further investigation towards improving rice tolerance to combined stress. |
| first_indexed | 2024-03-10T06:01:49Z |
| format | Article |
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| language | English |
| last_indexed | 2024-03-10T06:01:49Z |
| publishDate | 2021-10-01 |
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| spelling | doaj.art-97f8079c57b249beb299409ead8ebe4a2023-11-22T20:56:20ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672021-10-0122211169010.3390/ijms222111690Targeted Phytohormone Profiling Identifies Potential Regulators of Spikelet Sterility in Rice under Combined Drought and Heat StressMaria Vera Jesus Da Costa0Venkategowda Ramegowda1Sheshshayee Sreeman2Karaba N. Nataraja3Department of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore 560065, Karnataka, IndiaDepartment of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore 560065, Karnataka, IndiaDepartment of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore 560065, Karnataka, IndiaDepartment of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore 560065, Karnataka, IndiaRice cultivated under rainfed or semi-irrigated ecosystems is frequently exposed to a combination of drought and heat stress. As a sensitive crop at the reproductive stage, exposure to combined drought and heat stress will have a deleterious effect on yield. In this study, two rice cultivars with contrasting spikelet sterility, AVT2-5315 (low sterility) and AC35027 (high sterility), under combined stress were selected for physiological characterization and phytohormonal profiling at anthesis. Under combined stress, both cultivars did not differ in the physiological parameters such as relative water content, photosynthetic rate, light-adapted chlorophyll fluorescence and biomass, suggesting a similar source activity under stress. However, AVT2-5315 showed better yield due to better pollen and spikelet fertility than AC35027, suggesting its intrinsic tolerance ability under combined stress. Targeted profiling of 15 phytohormones from drought, heat and combined stress-treated flag leaf and spikelet tissues using LC–MS/MS showed increased accumulation of auxins (indole 3-acetic acid and indole 3-butyric acid) in flag leaves and jasmonic acid in spikelets of AVT2-5315, while there was increased accumulation of ethylene in flag leaves and methyl-jasmonate in spikelets of AC35027. Increased accumulation of these hormones correlated with key biosynthetic pathway genes. In the flag leaves, increased accumulation of auxins was correlated with increased transcript levels of <i>YUCCA-like gene 1</i> (<i>OsYUCCA1</i>) and <i>fish bone</i> (<i>OsFIB</i>), in AVT2-5315 under combined stress. In AC35027, increased ethylene content was correlated with expression of <i>1-aminocyclopropane-1-carboxylate synthase 1</i> (<i>OsASC1</i>) and <i>aminocyclopropane-1-carboxylic acid oxidase 2</i> (<i>OsACO2</i>). Similarly, in spikelets, increased accumulation of jasmonic acid in AVT2-5315 was correlated with expression of <i>allene oxide cyclase</i> (<i>OsAOC</i>) and <i>12-oxophytodienoic acid reductase 1</i> (<i>OsOPR1</i>). The mechanism of regulating spikelet sterility by these hormones needs further investigation towards improving rice tolerance to combined stress.https://www.mdpi.com/1422-0067/22/21/11690ricecombined drought and heat stressphytohormonesflag leafspikelets |
| spellingShingle | Maria Vera Jesus Da Costa Venkategowda Ramegowda Sheshshayee Sreeman Karaba N. Nataraja Targeted Phytohormone Profiling Identifies Potential Regulators of Spikelet Sterility in Rice under Combined Drought and Heat Stress International Journal of Molecular Sciences rice combined drought and heat stress phytohormones flag leaf spikelets |
| title | Targeted Phytohormone Profiling Identifies Potential Regulators of Spikelet Sterility in Rice under Combined Drought and Heat Stress |
| title_full | Targeted Phytohormone Profiling Identifies Potential Regulators of Spikelet Sterility in Rice under Combined Drought and Heat Stress |
| title_fullStr | Targeted Phytohormone Profiling Identifies Potential Regulators of Spikelet Sterility in Rice under Combined Drought and Heat Stress |
| title_full_unstemmed | Targeted Phytohormone Profiling Identifies Potential Regulators of Spikelet Sterility in Rice under Combined Drought and Heat Stress |
| title_short | Targeted Phytohormone Profiling Identifies Potential Regulators of Spikelet Sterility in Rice under Combined Drought and Heat Stress |
| title_sort | targeted phytohormone profiling identifies potential regulators of spikelet sterility in rice under combined drought and heat stress |
| topic | rice combined drought and heat stress phytohormones flag leaf spikelets |
| url | https://www.mdpi.com/1422-0067/22/21/11690 |
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