Silencing of ABCC13 transporter in wheat reveals its involvement in grain development, phytic acid accumulation and lateral root formation.
Silencing of ABCC13 transporter in wheat reveals its involvement in grain development, phytic acid accumulation and lateral root formation.
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DOI：
10.1093/jxb/erw224
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发表时间：
2016-07
影响因子：
6.9
通讯作者：
Pandey AK
中科院分区：
文献类型：
--
作者：
Bhati KK;Alok A;Kumar A;Kaur J;Tiwari S;Pandey AK
本研究证明了小麦ABCC转运蛋白（TaABCC 13）实现低植酸在谷物中的重要性，并证实了其先前推测的作用，在重金属解毒。低植酸是谷类作物所期望的性状，并且可以通过操纵参与其生物合成或其在液泡中的运输的基因来实现。之前，我们已经证明小麦TaABCC 13蛋白是一种功能性转运蛋白，主要参与重金属耐受性，并且是实现低植酸小麦的可能候选基因。在目前的研究中，RNA沉默被用来敲低TaABCC 13的表达，以评估其在小麦中的功能重要性。选择在种子或根中具有显著降低的TaABCC 13转录物的转基因植物用于进一步研究。纯合RNAi品系K1 B4和K4 G7表现出成熟谷粒（T4种子）中植酸含量降低34-22%。这些转基因株系的穗发育是有缺陷的，其特征在于减少籽粒灌浆和小穗数。转基因小麦的种子延迟发芽，但幼苗的活力不受影响。有趣的是，与非转基因株系相比，在TaABCC 13沉默株系中观察到侧根的早期出现。此外，这些品系在镉胁迫下的金属吸收和侧根发育也有缺陷。我们的研究结果表明TaABCC 13在侧根发生和增强对重金属的敏感性中的作用。综上所述，这些数据表明，小麦ABCC 13是功能重要的籽粒发育，并在重金属解毒过程中发挥重要作用。
This study demonstrates the importance of the wheat ABCC transporter (TaABCC13) for achieving low phytic acid in grains, and substantiates its previously speculated role during heavy metal detoxification. Low phytic acid is a trait desired in cereal crops and can be achieved by manipulating the genes involved either in its biosynthesis or its transport in the vacuoles. Previously, we have demonstrated that the wheat TaABCC13 protein is a functional transporter, primarily involved in heavy metal tolerance, and a probable candidate gene to achieve low phytate wheat. In the current study, RNA silencing was used to knockdown the expression of TaABCC13 in order to evaluate its functional importance in wheat. Transgenic plants with significantly reduced TaABCC13 transcripts in either seeds or roots were selected for further studies. Homozygous RNAi lines K1B4 and K4G7 exhibited 34–22% reduction of the phytic acid content in the mature grains (T4 seeds). These transgenic lines were defective for spike development, as characterized by reduced grain filling and numbers of spikelets. The seeds of transgenic wheat had delayed germination, but the viability of the seedlings was unaffected. Interestingly, early emergence of lateral roots was observed in TaABCC13-silenced lines as compared to non-transgenic lines. In addition, these lines also had defects in metal uptake and development of lateral roots in the presence of cadmium stress. Our results suggest roles of TaABCC13 in lateral root initiation and enhanced sensitivity towards heavy metals. Taken together, these data demonstrate that wheat ABCC13 is functionally important for grain development and plays an important role during detoxification of heavy metals.