ABSTRACT In our recent publication, we have shown that a member of the Laccase family, LACCASE2 (LAC2) acted as a negative regulator of lignin deposition in the root xylem tissue of Arabidopsis thaliana. LAC2 messenger RNA (mRNA) level was post-transcriptionally regulated by microRNA 397b, which showed increased expression under water and phosphate deficiency, resulting in the downregulation of LAC2 expression In this report, we have investigated root growth and lignin deposition in an economically important legume crop chickpea (Cicer arietinum L.) in response to natural drought in soil-grown condition. In contrast to the growth retardation of Arabidopsis root in mannitol-supplemented medium, chickpea root showed an increase in length in low soil moisture condition. Lignin estimation in the primary root showed an increase in lignin content, which was substantiated by staining of root xylem. Drought treatment enhanced the expression of four out of six LAC genes tested, while the expression of two was downregulated. Our preliminary study indicateed a molecular mechanism of lignin deposition in chickpea root xylem during drought.

中文翻译：

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干旱条件下鹰嘴豆根木质部木质素沉积

摘要在我们最近的出版物中，我们已经证明漆酶家族的一个成员 LACCASE2 (LAC2) 充当拟南芥根木质部组织中木质素沉积的负调节剂。LAC2 信使 RNA (mRNA) 水平受 microRNA 397b 的转录后调控，在缺水缺磷的情况下其表达增加，导致 LAC2 表达下调。作物鹰嘴豆 (Cicer arietinum L.) 响应土壤生长条件下的自然干旱。与拟南芥根在甘露醇补充培养基中的生长迟缓相反，鹰嘴豆根在低土壤水分条件下长度增加。初生根中的木质素估计显示木质素含量增加，根木质部染色证实了这一点。干旱处理增强了测试的六个 LAC 基因中四个的表达，而两个的表达被下调。我们的初步研究表明了干旱期间鹰嘴豆根木质部木质素沉积的分子机制。