Figure: Very-long-chain fatty acids restrict pericycle competence for callus formation and regeneration in Arabidopsis. (A) The VLCFA-deficient mutant cfr1 bypasses the inhibition of callus-forming capacity by solitary-root. (B) Adventitious shoot regenerated efficiently from the root-derived calluses of cfr1-1. (C) Expression pattern of the pericycle identity marker J0121 in the mature zone of WT, slr, and cfr1-1 on callus-inducing medium.
The differentiated organs or tissues in plants have a remarkable capability to regenerate new individuals under appropriate conditions. The in vitro regeneration system has been used extensively in plant biotechnology for decades. However, the molecular mechanism underlying the regeneration remains largely elusive.
Dr. Yuxin Hu’s lab at Institute of Botany, Chinese Academy of Sciences, reported that very-long-chain fatty acids (VLCFAs) or their derivatives act as the critical signal in restricting the callus-forming capacity in pericycle cells, and thus define the regeneration capability in Arabidopsis. By genetic screening, they identified the callus formation-related 1 (cfr1) mutant, which bypasses the inhibition of callus-forming capacity in roots by solitary-root (slr/iaa14). CFR1 encodes 3-ketoacyl-CoA synthase 1 (KCS1), which catalyzes the rate-limiting step of VLCFA biosynthesis. Biochemical and genetic analyses demonstrated that VLCFAs restricted the pericycle competence for callus formation, at least in part, by regulating the transcription of Aberrant Lateral Root Formation 4 (ALF4). These findings not only disclose a novel role of VLCFAs or their derivatives in defining the regeneration capacity of plant organs, but also shed light on the signaling that drives cell states in plants and the potential role of VLCFAs in regulating animal cell states.
The paper entitled ‘Very-long-chain fatty acids restrict regeneration capacity by confining pericycle competence for callus formation in Arabidopsis’ has been published in PNAS on April 18, 2016 (doi: 10.1073/pnas.1522466113). Baoshuan Shang and Dr. Chongyi Xu co-first authored the paper. This work is funded by the National Basic Research Program of China and the National Natural Science Foundation of China.
Article link: http://www.pnas.org/content/early/2016/04/15/1522466113.full