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Abstract

In the past few years many alpha- and beta-tubulin genes of different organisms have been cloned and studied, and in most systems studied they constitute multigene families. In plants, most studies have been done in Arabidopsis thaliana and Zea mays. In this paper, the study of mRNA accumulation by in situ hybridization and the activity of three maize alpha-tubulin gene promoters (tua1, tua2 and tua3) in transgenic tobacco plants are described. In maize, the expression of these three tubulin isotypes differ in the root and shoot apex and is associated with different groups of cells throughout the distinct stages of cell differentiation. In transgenic tobacco plants the promoters of the genes, fused to the uidA reporter gene (GUS), direct expression to the same tissues observed by in situ hybridization experiments. The tua1 promoter is mainly active in cortex-producing meristematic cells and in pollen, whereas tua3 is active in cells which are differentiating to form vascular bundles in the root and shoot apices. The accumulation of tua2 mRNA is detected by RNA blot in a similar form as tua1, but at a very much low level. In situ hybridization indicates that the tua2 mRNA specifically accumulates in the maize root epidermis. No GUS staining was detected in transgenic tobacco plants with the tua2 promoter. The difference in expression of the specific genes may be linked to processes where microtubules have different functions, suggesting that in plants, as in animals, there are differences in the function of the tubulin isotypes.

Genome-wide transcriptome analysis reveals molecular pathways involved in leafy head formation of Chinese cabbage (Brassica rapa)

“…For example, AtTUB1 is expressed in the cortical cells of the roots 30 , AtTUB9 is expressed in floral tissues 28 , and AtTUB8 is expressed in the vegetative and reproductive organs’ vasculature 30 . In most studies, tubulin genes have non-overlapping expression patterns 28,31,32 . Interestingly, in this study we found that BrTUB1 , BrTUB3 , and BrTUB4 all expressed in leaf tissue.…”

Genome-Wide Meta-Analysis of QTLs Associated with Root Traits and Implications for Maize Breeding

“…Sixteen known maize genes were identified within or near the fifteen MQTL regions. Six genes were identified within the MQTL regions: (i) pht1 gene localized in MQTL5.1 encodes for phosphate permease involved in phosphate ion uptake from soil [ 41 ]; (ii) YUC3 and YUC6 co-localized in MQTL4.7 and MQTL8.2, respectively, encode for flavin monooxygenase, which is known to play a role in auxin biosynthesis in maize roots [ 43 ]; (iii) DXS2 encodes deoxy xylulose synthase 2, but its molecular function is unknown, although it is highly expressed in the primary roots of maize seedlings [ 48 ]; (iv) root preferential 1 , RTP1 , gene localized in MQTL4.6 has also been reported to be highly expressed in roots and involved in suberin pathway [ 50 ]; (v) TUA4 identified in MQTL5.7 encodes for alpha-tubulin, having a role in structural maintenance and cell division in root cells [ 44 ].…”

Proteomic and gene expression analyses during bolting-related leaf color change in Brassica rapa

“…Genes encoding different isomers of the protein are differentially expressed in different tissues and development stages. A number of studies have been conducted on plant tubulins (Carpenter et al, 1992;Uribe et al, 1998;Xu et al, 1999;Li et al, 2007). Transgenic expression of GFP-TUA6 revealed that transverse microtubules form during the elongation stage of the inner cell wall in A. thaliana (Chan et al, 2011).…”