Molecular dynamics in germinating, endophyte-colonized quinoa seeds

Area of Science:

• Plant biology and microbiology
• Molecular plant-pathogen interactions

Background:

• Quinoa (Chenopodium quinoa) exhibits rapid germination and high salt tolerance.
• Quinoa seeds are consistently colonized by bacterial endophytes.
• Mitogen-activated protein kinase (MAPK) signaling pathways are crucial in plant development and stress responses.

Purpose of the Study:

• To investigate MAPK activities during early quinoa seed development.
• To assess the potential role of bacterial endophytes in quinoa's rapid germination and stress tolerance.

Main Methods:

• Monitoring MAPK activity in imbibed quinoa seeds using immunoblots.
• Biochemical assays for bacterial cellulolytic and pectinolytic activities.
• Gene sequencing for bacterial motility, biofilm, and compound synthesis.
• Cultivation-independent GyrA sequencing for endophyte diversity.

Main Results:

• Complex and dynamic MAPK activity profiles were observed in quinoa seeds and seedlings.
• Variations in MAPK patterns correlated with seed origin and likely endophyte assemblages.
• Bacterial endophytes demonstrated mucilage-degrading abilities, enabling colonization of non-host species (chia).

Conclusions:

• Quinoa endophytes possess motility, cell wall-loosening, and elicitor-generating capabilities.
• These bacterial traits can drive host cell expansion and activate MAPK signaling.
• Endophytes may facilitate rapid germination and prime seeds for stress tolerance, with potential for transfer to other crops.