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This work aims to analyze the relationship between root growth, mitogen-activated protein kinase (MAPK), auxin signaling, and cell cycle-related gene expression in cadmium (Cd)-stressed rice. The role of MAPKs in auxin signal modification and cell cycle-related gene expression during root growth was investigated by disrupting MAPK signaling using the MAPKK inhibitor PD98059 (PD). Treatment with Cd caused a significant accumulation of Cd in the roots. A Cd-specific probe showed that Cd is mainly localized in the meristematic zone and vascular tissues. Perturbation of MAPK signaling using PD significantly suppressed root system growth under Cd stress. The transcription of six MAPK genes was inhibited by Cd compared to the control. Detection using DR5-GUS transgenic rice showed that the intensity and distribution pattern of GUS staining was similar in roots treated with PD or Cd, whereas in Cd plus PD-treated roots, the GUS staining pattern was similar to that of the control, which indicates a close association of MAPK signaling with auxin homeostasis under control and Cd stress conditions. The expression of most key genes of auxin signaling, including OsYUCCA, OsPIN, OsARF, and OsIAA, and of most cell cycle-related genes, was negatively regulated by MAPKs under Cd stress. These results suggest that the MAPK pathway plays specific roles in auxin signal transduction and in the control of the cell cycle in response to Cd stress. Altogether, MAPKs take part in the regulation of root growth via auxin signal variation and the modified expression of cell cycle-related genes in Cd-stressed rice. A working model for the function of MAPKs in rice root systems grown under Cd stress is proposed.

In this study, we examined the relationship between abscisic acid (ABA), auxin, and mitogen-activated protein kinase (MAPK) signaling and the cell cycle in rice (Oryza sativa L. cv. Zhonghua No. 11) roots. Root system growth was significantly promoted by 0.1 nM ABA but markedly inhibited by 0.3 mM Tungstate (TS, an ABA biosynthesis inhibitor). Detection of plants treated with DRB (an RNA synthesis inhibitor, 5,6-dichlorobenzimidazole 1-b-D-ribofuranoside), TIBA (2,3,5-triiodobenzoic acid, an inhibitor of polar auxin transport), or BFA (brefeldin, a protein transport inhibitor) using DR5-GUS staining revealed that ABA regulates the distribution of auxin via transcription and transport pathways. The expression of some auxin-and cell cycle-related genes, as well as several ABA or MAPK genes, was differentially regulated in roots by ABA and TS at 7 or 11 days, indicating that a certain level of ABA action may primarily target specific genes involved in MAPK and auxin signaling and the cell cycle at a given developmental stage. The results suggest that an appropriate level of ABA determines auxin homeostasis through controlling gene expression and the distribution of auxin, and that ABA regulates the auxin and MAPK signaling pathways and influences cell-cycle progression. Overall, ABA plays positive roles in regulating root system growth by modulating MAPK and auxin signaling and the cell cycle. Our findings help elucidate the integrative effects of ABA, auxin, and MAPK signaling and the cell cycle on root growth. We propose a working model for the role of ABA in root system growth.

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The Advanced Encryption Standard (AES) was specified in 2001 by the National Institute of Standards and Technology. Our attempt is to define the hardware rule about hardware calculation and to find further reduce for the size of AES, by seeking to other normal bases.Finally, we give the result that our hardware implementation is better than the previous results.