Ascorbate-Deficient vtc2 Mutants in Arabidopsis Do Not Exhibit Decreased Growth.
Ascorbate-Deficient vtc2 Mutants in Arabidopsis Do Not Exhibit Decreased Growth.
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DOI：
10.3389/fpls.2016.01025
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发表时间：
2016
影响因子：
5.6
通讯作者：
Golz JF
中科院分区：
文献类型：
--
作者：
Lim B;Smirnoff N;Cobbett CS;Golz JF
In higher plants the L-galactose pathway represents the major route for ascorbate biosynthesis. The first committed step of this pathway is catalyzed by the enzyme GDP-L-galactose phosphorylase and is encoded by two paralogs in Arabidopsis – VITAMIN C2 (VTC2) and VTC5. The first mutant of this enzyme, vtc2-1, isolated via an EMS mutagenesis screen, has approximately 20–30% of wildtype ascorbate levels and has been reported to have decreased growth under standard laboratory conditions. Here, we show that a T-DNA insertion into the VTC2 causes a similar reduction in ascorbate levels, but does not greatly affect plant growth. Subsequent segregation analysis revealed the growth defects of vtc2-1 mutants segregate independently of the vtc2-1 mutation. These observations suggest that it is the presence of an independent cryptic mutation that affects growth of vtc2-1 mutants, and not the 70–80% decrease in ascorbate levels that has been assumed in past studies.
