Transport of boron by the tassel-less1 aquaporin is critical for vegetative and reproductive development in maize

Durbak, AR, Phillips KA, Pike S, O'Neill MA, Mares J, Gallavotti A, Malcomber S, Gassmann W, McSteen P.  2014.  

Journal:

Plant Cell

Issue Number:

26

Pages:

2978-2995

Abstract:

The element boron (B) is an essential plant micronutrient, and B deficiency results in significant crop losses worldwide. The
maize (Zea mays) tassel-less1 (tls1) mutant has defects in vegetative and inflorescence development, comparable to the
effects of B deficiency. Positional cloning revealed that tls1 encodes a protein in the aquaporin family co-orthologous to
known B channel proteins in other species. Transport assays show that the TLS1 protein facilitates the movement of B and
water into Xenopus laevis oocytes. B content is reduced in tls1 mutants, and application of B rescues the mutant phenotype,
indicating that the TLS1 protein facilitates the movement of B in planta. B is required to cross-link the pectic polysaccharide
rhamnogalacturonan II (RG-II) in the cell wall, and the percentage of RG-II dimers is reduced in tls1 inflorescences, indicating
that the defects may result from altered cell wall properties. Plants heterozygous for both tls1 and rotten ear (rte), the
proposed B efflux transporter, exhibit a dosage-dependent defect in inflorescence development under B-limited conditions,
indicating that both TLS1 and RTE function in the same biological processes. Together, our data provide evidence that TLS1 is
a B transport facilitator in maize, highlighting the importance of B homeostasis in meristem function.

Related External URL:

http://www.plantcell.org/content/26/7/2978.full
Citation:
Durbak, AR, Phillips KA, Pike S, O'Neill MA, Mares J, Gallavotti A, Malcomber S, Gassmann W, McSteen P.  2014.  Transport of boron by the tassel-less1 aquaporin is critical for vegetative and reproductive development in maize. Plant Cell. (26):2978-2995.