Developmental plasticity is critical for plants to adapt to constantly changing environments. Plant root hairs displaydramatic plasticity under different environments and therefore play crucial roles in defense agains...Developmental plasticity is critical for plants to adapt to constantly changing environments. Plant root hairs displaydramatic plasticity under different environments and therefore play crucial roles in defense against environmentalstressors. Here, we report the isolation of an Arabidopsis mutant, salinity over-sensitive mutant 1-1 (som1-1), also exhibitingroot hair developmental defects. Map-based cloning and allelic analyses confirmed that som1-1 is a new mutantallele of SPIRRIG (SPI), which encodes a Beige and Chediak Higashi (BEACH) domain-containing protein. SPI has beenreported to facilitate actin dependent root hair development by temporally and spatially regulating the expressionof BRICK1 (BRK1), a subunit of the SCAR/WAVE actin nucleating promoting complex. Our living cell imaging examinationsrevealed that salt stress induces an altered actin organization in root hair that mimics those in the spi mutant,implying SPI may respond to salt stress induced root hair plasticity by modulating actin cytoskeleton organization.Furthermore, we found BRK1 is also involved in root hair developmental change under salt stress, and overexpressionof BRK1 resulted in root hairs over-sensitive to salt stress as those in spi mutant. Moreover, based on biochemicalanalyses, we found BRK1 is unstable and SPI mediates BRK1 stability. Functional loss of SPI results in the accumulationof steady-state of BRK1.展开更多
基金supported by the National Natural Science Foundation of China to LA(31470290,32070198)the Chinese Universities Scientific Fund to LA(2452020180)+1 种基金the National Science Foundation grants IOS-1923589 and IOS-2127485 and Department of Energy grant DE-SC0020358 to John Sthe Natural Science Foundation of Shaanxi Province to Jingxia S(2023-JC-YB-158).
文摘Developmental plasticity is critical for plants to adapt to constantly changing environments. Plant root hairs displaydramatic plasticity under different environments and therefore play crucial roles in defense against environmentalstressors. Here, we report the isolation of an Arabidopsis mutant, salinity over-sensitive mutant 1-1 (som1-1), also exhibitingroot hair developmental defects. Map-based cloning and allelic analyses confirmed that som1-1 is a new mutantallele of SPIRRIG (SPI), which encodes a Beige and Chediak Higashi (BEACH) domain-containing protein. SPI has beenreported to facilitate actin dependent root hair development by temporally and spatially regulating the expressionof BRICK1 (BRK1), a subunit of the SCAR/WAVE actin nucleating promoting complex. Our living cell imaging examinationsrevealed that salt stress induces an altered actin organization in root hair that mimics those in the spi mutant,implying SPI may respond to salt stress induced root hair plasticity by modulating actin cytoskeleton organization.Furthermore, we found BRK1 is also involved in root hair developmental change under salt stress, and overexpressionof BRK1 resulted in root hairs over-sensitive to salt stress as those in spi mutant. Moreover, based on biochemicalanalyses, we found BRK1 is unstable and SPI mediates BRK1 stability. Functional loss of SPI results in the accumulationof steady-state of BRK1.
