近日，華南農(nóng)大鐘珉團(tuán)隊在PCE發(fā)表了題為《HB52-PUT2 Module-Mediated Polyamine Shoot-to-Root Movement Regulates Salt Stress Tolerance in Tomato》的研究論文，揭示了HB52-PUT2模塊介導(dǎo)的多胺莖根運動調(diào)節(jié)番茄耐鹽性。

土壤鹽分嚴(yán)重限制了作物質(zhì)量和產(chǎn)量。植物已經(jīng)發(fā)展出各種策略來減輕鹽脅迫的負(fù)面效應(yīng)，包括通過多胺吸收轉(zhuǎn)運蛋白（PUTs）進(jìn)行多胺再分配。

然而，PUTs在鹽脅迫期間改變多胺轉(zhuǎn)運過程的機(jī)制尚未完全闡明。

在本研究中，作者展示了參與多胺從莖到根運輸?shù)腜UT2的破壞會導(dǎo)致番茄對鹽脅迫的敏感表型。此外，酵母單雜交篩選出一個與PUT2相互作用的HD-Zip轉(zhuǎn)錄因子HB52，而HB52的功能喪失也導(dǎo)致了對鹽脅迫的敏感性增加，而HB52過表達(dá)系表現(xiàn)出改善的耐鹽性。

進(jìn)一步的分子分析表明，HB52直接激活了PUT2的表達(dá)，并通過促進(jìn)多胺從莖到根的移動性來促進(jìn)Na 外流。

綜上，這項研究揭示了一個與同源框蛋白調(diào)節(jié)因子相關(guān)的協(xié)同轉(zhuǎn)錄調(diào)控網(wǎng)絡(luò)，該調(diào)節(jié)因子在鹽脅迫下促進(jìn)多胺的長距離運輸。

Soil salinity severely restricts crop quality and yields. Plants have developed various strategies to alleviate salinity stress's negative effects, including polyamine redistribution by polyamine uptake transporters (PUTs). However, the mechanisms by which PUTs alter polyamine translocation processes during salt stress have not been fully elucidated. Here, we show that disruption of PUT2, which is involved in polyamine shoot-to-root transport, results in salt sensitivity phenotypes in tomato. Moreover, yeast one-hybrid screened for an HD-Zip transcription factor HB52 that interacts with PUT2, and loss of function of HB52 also led to increased sensitivity to salt stress, whereas HB52-overexpression lines exhibited improved salt tolerance. Furthermore, molecular analyses demonstrated that HB52 directly activated the expression of PUT2 and facilitated Na  efflux by promoting polyamine shoot-to-root mobility. This study uncovers a synergistic transcriptional regulatory network associated with a homeobox protein regulator that promotes polyamine long-distance transport under salt stress.

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