Almoguera Concepción, Prieto-Dapena Pilar, Carranco Raúl, Ruiz José Luis, Jordano Juan
IRNAS, Av. Reina Mercedes 10, 41012 Sevilla, CSIC, Spain.
IPBLN, Av. del Conocimiento 17, 18016 Armilla, Granada, CSIC, Spain.
Plants (Basel). 2020 Mar 6;9(3):335. doi: 10.3390/plants9030335.
Heat Stress Factor A9 (A9), a seed-specific transcription factor contributing to seed longevity, also enhances phytochrome-dependent seedling greening. The RNA-seq analyses of imbibed-seed transcripts here reported indicated potential additional effects of A9 on cryptochrome-mediated blue-light responses. These analyses also suggested that in contrast to the A9 effects on longevity, which require coactivation by additional factors as A4a, A9 alone might suffice for the enhancement of photomorphogenesis at the seedling stage. We found that upon its seed-specific overexpression, A9 indeed enhanced the expected blue-light responses. Comparative loss-of-function analyses of longevity and greening, performed by similar expression of dominant-negative and inactive forms of A9, not only confirmed the additional greening effects of A9, but also were consistent with A9 not requiring A4a (or additional factors) for the greening effects. Our results strongly indicate that A9 would differentially regulate seed longevity and photomorphogenesis at the seedling stage, A9 alone sufficing for both the phytochrome- and cryptochrome-dependent greening enhancement effects.
热应激因子A9（A9）是一种有助于种子寿命的种子特异性转录因子，它还能增强光敏色素依赖性的幼苗绿化。本文报道的吸胀种子转录本的RNA测序分析表明，A9对隐花色素介导的蓝光反应可能还有其他潜在影响。这些分析还表明，与A9对种子寿命的影响（需要A4a等其他因子的共激活）不同，A9单独就可能足以增强幼苗阶段的光形态建成。我们发现，在种子特异性过表达时，A9确实增强了预期的蓝光反应。通过类似表达显性负性和无活性形式的A9进行的种子寿命和绿化的功能丧失比较分析，不仅证实了A9对绿化的额外影响，而且与A9在绿化影响方面不需要A4a（或其他因子）一致。我们的结果有力地表明，A9在幼苗阶段会差异调节种子寿命和光形态建成，A9单独就足以产生光敏色素和隐花色素依赖性的绿化增强效应。
