Abstract
The parasitic plant Striga (Striga hermonthica) invades the host root through the formation of a haustorium and has detrimental impacts on cereal crops. The haustorium results from the prehaustorium, which is derived directly from the differentiation of the Striga radicle. The molecular mechanisms leading to radicle differentiation shortly after germination remain unclear. In this study, we determined the developmental programs that regulate terminal prehaustorium formation in S. hermonthica at cellular resolution. We showed that shortly after germination, cells in the root meristem undergo multiplanar divisions. During growth, the meristematic activity declines and associates with reduced expression of the stem cell regulator PLETHORA1 and the cell cycle genes CYCLINB1 and HISTONE H4. We also observed a basal localization of the PIN-FORMED (PIN) proteins and a decrease in auxin levels in the meristem. Using the structural layout of the root meristem and the polarity of outer-membrane PIN proteins, we constructed a mathematical model of auxin transport that explains the auxin distribution patterns observed during S. hermonthica root growth. Our results reveal a fundamental molecular and cellular framework governing the switch of S.
Original language | English (US) |
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Pages (from-to) | 2281-2297 |
Number of pages | 17 |
Journal | PLANT PHYSIOLOGY |
Volume | 189 |
Issue number | 4 |
DOIs | |
State | Published - Aug 2022 |
Bibliographical note
Funding Information:This study was supported by King Abdullah University of Science and Technology (KAUST) baseline funding given to Ikram Blilou and by the Bill and Melinda Gates Foundation grant OPP1194472 given to Salim Al-Babili. Realistic root models developed in the frame of Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) and the Russian Foundation for Basic Research (RFBR) joint project RFBR-DFG 19-54-12013. Mathematical modeling was supported by FWNR-2022-0020.
Publisher Copyright:
© 2022 American Society of Plant Biologists. All rights reserved.
ASJC Scopus subject areas
- Physiology
- Genetics
- Plant Science