Aquaporin AtTIP5;1 negatively regulates nitric oxide-promoted lateral root development by affecting auxin transport and homeostasis of reactive oxygen species in roots of Arabidopsis.

چکیده اصلی

Aquaporins and nitric oxide (NO) are essential regulators of lateral root (LR) development in plants. However, whether an aquaporin could modulate NO-affected LR formation remains elusive. Here, we show that the tonoplast intrinsic aquaporin protein AtTIP5;1 negatively regulates NO-promoted LR development. AtTIP5;1 is highly expressed in root pericycle cells. AtTIP5;1 overexpression causes significant suppression of LR formation induced by sodium nitroprusside (SNP), an NO donor. Moreover, AtTIP5;1 overexpression results in a clear decrease in NO accumulation in the roots. The application of exogenous auxin influx inhibitor naphthoxyacetic acid boosts the effect of AtTIP5;1 on LR growth evoked by SNP, whereas the auxin efflux inhibitors N-1-naphthylphthalamic acid and 2,3,5-triiodobenzoic acid notably attenuate this effect. In addition, AtTIP5;1 overexpression leads to elevated hydrogen peroxide levels, decreased superoxide anion accumulation, enhanced superoxide dismutase activity, and reduced activities of catalase, ascorbate peroxidase, and peroxidase in roots under SNP treatment. These results suggest that AtTIP5;1 may inhibit NO-facilitated LR development by reducing NO accumulation, affecting auxin transport, and altering ROS homeostasis in Arabidopsis.

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