Limits...
Dihydroxyacid dehydratase is important for gametophyte development and disruption causes increased susceptibility to salinity stress in Arabidopsis.

Zhang C, Pang Q, Jiang L, Wang S, Yan X, Chen S, He Y - J. Exp. Bot. (2014)

Bottom Line: In addition, reduced expression of DHAD in knockdown mutants resulted in a reduction in the accumulation of all three BCAAs in roots and, as a consequence, led to a shorter root phenotype, which could be restored by an exogenous supplement of free BCAAs.This would be the second amino acid shown to confer such a function in addition to the well-documented proline.Our results provide evidence that BCAA biosynthesis plays important roles in gametophyte and root development, and BCAA homeostasis contributes to the adaptation of Arabidopsis to salinity stress.

View Article: PubMed Central - PubMed

Affiliation: National Maize Improvement Centre of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.

No MeSH data available.


Related in: MedlinePlus

AtDHAD gene structure, mutation sites, and phenotype of loss-of-function mutant alleles. (A) Exon-intron structure and the T-DNA insertion sites. Each arrow indicates a T-DNA insertion site in different mutant alleles: 1, dhad-1; 2, dhad-2; 3, dhad-3; 4, dhad-4. (B–D) Alexander staining of pollen grains from the WT (B), DHAD-3/dhad-3 (C), and DHAD-4/dhad-4 plants (D). Arrows highlight the smaller pollen grains. Bar, 100 μm. (E) Statistical counting of the aborted pollen grains. Error bars indicate standard error. (F–H) Examination of open siliques from WT (F), DHAD-3/dhad-3 (G), and DHAD-4/dhad-4 plants (H). Arrows highlight the aborted ovules. (I) Statistical counting of the aborted ovules. Error bars indicate standard error. This figure is available in colour at JXB online.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4321549&req=5

Figure 2: AtDHAD gene structure, mutation sites, and phenotype of loss-of-function mutant alleles. (A) Exon-intron structure and the T-DNA insertion sites. Each arrow indicates a T-DNA insertion site in different mutant alleles: 1, dhad-1; 2, dhad-2; 3, dhad-3; 4, dhad-4. (B–D) Alexander staining of pollen grains from the WT (B), DHAD-3/dhad-3 (C), and DHAD-4/dhad-4 plants (D). Arrows highlight the smaller pollen grains. Bar, 100 μm. (E) Statistical counting of the aborted pollen grains. Error bars indicate standard error. (F–H) Examination of open siliques from WT (F), DHAD-3/dhad-3 (G), and DHAD-4/dhad-4 plants (H). Arrows highlight the aborted ovules. (I) Statistical counting of the aborted ovules. Error bars indicate standard error. This figure is available in colour at JXB online.

Mentions: The AtDHAD gene contains 14 exons and 13 introns, and encodes a putative 608 amino acid protein (Fig. 2A). To investigate the biological importance of AtDHAD in plant development and stress tolerance, we obtained five T-DNA insertion lines from the SALK and WiscDsLox collections (Alonso et al., 2003; Woody et al., 2007), named hereinafter dhad-1 (SALK_062347), dhad-2 (SALK_075098/SALK_130404), dhad-3 (WiscDsLoxHs135_03D), and dhad-4 (WiscDsLoxHs184_11A). The insertions sites of all these mutant lines were verified by sequencing the junctions of the gene/T-DNA. It should be noted that the sequencing results showed that SALK_075098 and SALK_130404 harbour T-DNA at the same location, so only SALK_130404 was chosen for further study. The insertions of dhad-1 and dhad-2 reside in the putative promoter or 5’UTR regions with 273bp and 88bp upstream of the start codon, respectively. The insertions of dhad-3 and dhad-4 locate in exon 1 and intron 3, respectively (Fig. 2A).


Dihydroxyacid dehydratase is important for gametophyte development and disruption causes increased susceptibility to salinity stress in Arabidopsis.

Zhang C, Pang Q, Jiang L, Wang S, Yan X, Chen S, He Y - J. Exp. Bot. (2014)

AtDHAD gene structure, mutation sites, and phenotype of loss-of-function mutant alleles. (A) Exon-intron structure and the T-DNA insertion sites. Each arrow indicates a T-DNA insertion site in different mutant alleles: 1, dhad-1; 2, dhad-2; 3, dhad-3; 4, dhad-4. (B–D) Alexander staining of pollen grains from the WT (B), DHAD-3/dhad-3 (C), and DHAD-4/dhad-4 plants (D). Arrows highlight the smaller pollen grains. Bar, 100 μm. (E) Statistical counting of the aborted pollen grains. Error bars indicate standard error. (F–H) Examination of open siliques from WT (F), DHAD-3/dhad-3 (G), and DHAD-4/dhad-4 plants (H). Arrows highlight the aborted ovules. (I) Statistical counting of the aborted ovules. Error bars indicate standard error. This figure is available in colour at JXB online.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4321549&req=5

Figure 2: AtDHAD gene structure, mutation sites, and phenotype of loss-of-function mutant alleles. (A) Exon-intron structure and the T-DNA insertion sites. Each arrow indicates a T-DNA insertion site in different mutant alleles: 1, dhad-1; 2, dhad-2; 3, dhad-3; 4, dhad-4. (B–D) Alexander staining of pollen grains from the WT (B), DHAD-3/dhad-3 (C), and DHAD-4/dhad-4 plants (D). Arrows highlight the smaller pollen grains. Bar, 100 μm. (E) Statistical counting of the aborted pollen grains. Error bars indicate standard error. (F–H) Examination of open siliques from WT (F), DHAD-3/dhad-3 (G), and DHAD-4/dhad-4 plants (H). Arrows highlight the aborted ovules. (I) Statistical counting of the aborted ovules. Error bars indicate standard error. This figure is available in colour at JXB online.
Mentions: The AtDHAD gene contains 14 exons and 13 introns, and encodes a putative 608 amino acid protein (Fig. 2A). To investigate the biological importance of AtDHAD in plant development and stress tolerance, we obtained five T-DNA insertion lines from the SALK and WiscDsLox collections (Alonso et al., 2003; Woody et al., 2007), named hereinafter dhad-1 (SALK_062347), dhad-2 (SALK_075098/SALK_130404), dhad-3 (WiscDsLoxHs135_03D), and dhad-4 (WiscDsLoxHs184_11A). The insertions sites of all these mutant lines were verified by sequencing the junctions of the gene/T-DNA. It should be noted that the sequencing results showed that SALK_075098 and SALK_130404 harbour T-DNA at the same location, so only SALK_130404 was chosen for further study. The insertions of dhad-1 and dhad-2 reside in the putative promoter or 5’UTR regions with 273bp and 88bp upstream of the start codon, respectively. The insertions of dhad-3 and dhad-4 locate in exon 1 and intron 3, respectively (Fig. 2A).

Bottom Line: In addition, reduced expression of DHAD in knockdown mutants resulted in a reduction in the accumulation of all three BCAAs in roots and, as a consequence, led to a shorter root phenotype, which could be restored by an exogenous supplement of free BCAAs.This would be the second amino acid shown to confer such a function in addition to the well-documented proline.Our results provide evidence that BCAA biosynthesis plays important roles in gametophyte and root development, and BCAA homeostasis contributes to the adaptation of Arabidopsis to salinity stress.

View Article: PubMed Central - PubMed

Affiliation: National Maize Improvement Centre of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.

No MeSH data available.


Related in: MedlinePlus