Skewing in Arabidopsis roots involves disparate environmental signaling pathways

Background: Skewing root patterns provide key insights into root growth strategies and mechanism that produce root architectures Roots exhibit skewing and waving when grown on a tilted, impenetrable surface, and while the genetics guiding these morphologies have been examined, the underlying molecular mechanisms of skewing and waving remain unclear. In this study, transcriptome data were derived from two Arabidopsis ecotypes, WS and Col-0, under three tilted growth conditions in order to identify candidate genes involved in skewing. WS is a skewing ecotype. Col-0 is a non-skewing ecotype. Results: This work identifies a number of genes that are likely involved in skewing, using growth conditions that differentially affect skewing and waving. Comparing the gene expression profiles of WS and Col-0 in different tilted growth conditions identified 11 candidate genes as potentially involved in the control of skewing. These 11 genes are involved in several different cellular processes, including sugar transport, salt signaling, cell wall organization, and hormone signaling. Conclusions: Many of the 11 identified genes are involved in signaling and perception, rather than the physical restructuring of roots, leading to the conclusion that root skewing is enabled through diverse environmental signaling pathways. These findings revealed further insights into the molecular mechanisms behind root skewing.

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Schultz ER, Zupanska AK, Sng NJ, Paul AL, Ferl RJ