Department of Bioengineering, Zhuhai Campus of Zunyi Medical University, 519040, Zhuhai, China.
Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, 510631, Guangzhou, China.
BMC Genomics. 2023 Mar 16;24(1):119. doi: 10.1186/s12864-023-09219-2.
HR (hairy root) has emerged as a valuable tissue for the rapid characterization of plant gene function and enzyme activity in vivo. AhGLK1 (Arachis hypogaea L. golden2-like 1) is known to play a role in post-drought recovery. However, it is unclear (a) whether HR has properties that are distinct from those of PR (primary root); and (b) which gene networks are regulated by AhGLK1 in response to drought stress and recovery in peanut.
We found that cells of the root tip cortex were larger in HR than in PR, while a total of 850 differentially expressed genes (DEGs) were identified in HR compared to PR. Eighty-eight of these DEGs, relating to chlorophyll and photosynthesis, were upregulated in HR. In addition, AhGLK1-OX (AhGLK1-overexpressing) HR showed a green phenotype, and had a higher relative water content than 35 S::eGFP (control) HR during drought stress. RNA-seq analysis showed that 74 DEGs involved both in the drought response and the post-drought recovery process were significantly enriched in the galactose metabolism pathway. GO terms enrichment analysis revealed that 59.19%, 29.79% and 17.02% of the DEGs mapped to the 'biological process' (BP), 'molecular function' (MF) and 'cellular component' (CC) domains, respectively. Furthermore, 20 DEGs involved in post-drought recovery were uniquely expressed in AhGLK1-OX HR and were significantly enriched in the porphyrin metabolism pathway. GO analysis showed that 42.42%, 30.30% and 27.28% of DEGs could be assigned to the BP, MF and CC domains, respectively. Transcription factors including bHLH and MYB family members may play a key role during drought stress and recovery.
Our data reveal that HR has some of the characteristics of leaves, indicating that HR is suitable for studying genes that are mainly expressed in leaves. The RNA-seq results are consistent with previous studies that show chlorophyll synthesis and photosynthesis to be critical for the role of AhGLK1 in improving post-drought recovery growth in peanut. These findings provide in-depth insights that will be of great utility for the exploration of candidate gene functions in relation to drought tolerance and/or post-drought recovery ability in peanut.
发根（HR）已成为一种有价值的组织，可用于快速体内鉴定植物基因功能和酶活性。已知 AhGLK1（花生金色 2 样 1）在旱后恢复中发挥作用。然而，尚不清楚（a）HR 是否具有与 PR（主根）不同的特性；以及（b）哪些基因网络受 AhGLK1 调控以响应花生干旱胁迫和恢复。
我们发现根尖皮层细胞在 HR 中比在 PR 中更大，而与 PR 相比，HR 中总共鉴定出 850 个差异表达基因（DEG）。这些 DEG 中有 88 个与叶绿素和光合作用有关，在 HR 中上调。此外，AhGLK1-OX（AhGLK1 过表达）HR 表现出绿色表型，并且在干旱胁迫期间，其相对含水量高于 35S::eGFP（对照）HR。RNA-seq 分析表明，74 个涉及干旱响应和旱后恢复过程的 DEG 在半乳糖代谢途径中显著富集。GO 术语富集分析表明，DEG 中有 59.19%、29.79%和 17.02%分别映射到“生物过程”（BP）、“分子功能”（MF）和“细胞组分”（CC）领域。此外，20 个参与旱后恢复的 DEG 仅在 AhGLK1-OX HR 中表达，并在卟啉代谢途径中显著富集。GO 分析表明，42.42%、30.30%和 27.28%的 DEG 可分别分配到 BP、MF 和 CC 领域。转录因子，包括 bHLH 和 MYB 家族成员，可能在干旱胁迫和恢复中发挥关键作用。
我们的数据表明 HR 具有叶片的某些特征，表明 HR 适合研究主要在叶片中表达的基因。RNA-seq 结果与先前的研究一致，表明叶绿素合成和光合作用对于 AhGLK1 提高花生旱后恢复生长的作用至关重要。这些发现为深入探索与花生耐旱性和/或旱后恢复能力相关的候选基因功能提供了重要依据。
