Maize Genetics Cooperation Newsletter vol 88 2014

New EMS-induced allele of terminal ear1 (te1) allele in the B73 background

Best NB¹, Budka JS¹, Schulz B², Weil C³, and Dilkes BP¹

1 Department of Horticulture & Landscape Architecture; Purdue University; West Lafayette, IN

2 Department of Botany &Plant Pathology; Purdue University; West Lafayette, IN

3 Department of Agronomy; Purdue University; West Lafayette, IN

email: [email protected] and [email protected]

The maize gene terminal ear1 locus encodes a Mei-2-like gene with multiple RNA-recognition motifs [1]. We have identified a new allele of te1 in the B73 genetic background while screening a M2 EMS-treated population from the maize TILLING (Targeting Induced Local Lesions IN Genomes) project. The population was phenotyped in the summer of 2011 in West Lafayette, IN (Figure 1). Plants in family 04IAB73PS110D5 were segregating for wild type and terminal ear phenotypes in a 3:1 fashion, consistent with a recessive mutation. Due to similarities in phenotype of te1 and our mutant (04IAB73PS110D5) an allelism test was performed. A homozygous plant from maize genetics stock number 326D (te1-1) was crossed to a phenotypically affected 04IAB73PS110D5 individual and 12 progeny were planted in the summer of 2013. All 12 progeny exhibited the te1 phenotype. Thus, we refer to this new allele of te1 as te1-8. This allele appears to be a slightly weaker allele than te1-1 due to lower number of internodes with length asymmetry (Figure 1B,C) and also production of some terminal staminate florets [2,3].

A second family, (04IAB73PS122A6), also showed a striking similarity to te1 (Figure 2). Plants were also segregating in a 3:1 fashion in the EMS-treated M2 generation, consistent with a recessive mutation in this line as well. However, allelism tests have not been conducted and we provisionally refer to this as terminal ear-like-*122A6 (tel-*122A6). This mutant is also in an EMS treated B73 background. The mutant, tel-*122A6, produces more staminate florets than te1-8 (Figure 2B), however it has a more severe internode length asymmetry phenotype (Figure 2C) [2,3]. Seeds carrying the te1-8 and tel-*122A6 alleles are being deposited at the Maize Genetics Cooperation stock center.

Figure 1. Mature plants of te1-8 in a M2 segregating population. (A) te1-8, (B) te1-8 stem with leaves removed, and (C) close up of te1-8 stem showing asymmetric internodes.

Figure 2. Mature plants of tel-*122A6 in a M2 segregating population. (A) tel-*122A6, (B) close up of tel-*122A6 tassel, and (C) tel-*122A6 stem with leaves removed showing asymmetric internodes.

References

[1] Veit B, Briggs SP, Schmidt RJ, Yanofsky MF, Hake S (1998) Regulation of leaf initiation by the terminal ear1 gene of maize. Nature 393:166-168.

[2] Veit B (1998) Leaf initiation: New developments in an expanding field. Plant Cell 10:1407-1411

[3] Irish EE (1996) Regulation of sex determination in maize. BioEssays. 18:363-369.

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