Understanding the role of the novel gene, SENSITIVE-TO-FREEZING10 (SFR10), in integrating freezing and light acclimation in plants

面对不可预测的气候，提高作物对包括冰冻在内的压力的抵御能力是农业面临的一项关键挑战。在冬季来临之前，植物通过转录和代谢的改变来适应寒冷的环境，从而提高植物的抗冻能力。以前已经研究过光和冷驯化之间的相互作用，光似乎对建立抗冻/耐寒性很重要，特别是在长日照条件下。具体来说，与光合电子传递相关的参数在冷驯化过程中受到光照水平的影响，在正常生长温度下提高光照强度可能会诱导抗冻性。光也影响冷调控基因的表达水平，然而，光和冷驯化之间相互作用的分子基础尚不清楚。我们已经证明，基因敏感性- to - freezing 10 （SFR10）编码一个叶绿体定位的蛋白，该蛋白是拟南芥对冷冻胁迫的完全冷驯化和对强光水平的光合驯化所必需的（未发表的数据）。同源基因存在于一系列单子叶和双子叶植物中，使SFR10成为提高作物生产力和抗逆性的有力候选基因。该项目将采用互补的方法来了解SFR10效应的机制基础，同时揭示其分子进化和突变对抗冻能力的增强负责。该项目将首先全面表征SFR10在正常和逆境条件下对冷驯化诱导的抗冻性、光合适应性、生产力和代谢物含量的丧失和获得的功能，并检查gfp标记的SFR10在冷强光下的定位。对SFR10蛋白序列的初步检测发现了一个潜在的dna结合域，因此SFR10可能调节其他基因的表达。该候选人将寻求鉴定SFR10的叶绿体定位DNA和蛋白质相互作用物，并将分析和验证现有的RNAseq数据以鉴定SFR10应答转录本。此外，我们将在正向选择的系统发育分析框架内，对GenBank中来自不同气候的被子植物的数百个SFR10同源物进行互补进化分析。这将使我们能够确定SFR10蛋白中负责增加抗冻能力的潜在氨基酸开关。编码这些氨基酸开关的snp将通过用修饰过的sfr10序列补充完全丧失功能的sfr10突变体，以及在时间允许的情况下，通过创建CRISPR-Cas修饰的甘油三酯，并测试它们的抗冻性和光适应性来进行经验性查询。

Improving crop resilience to stresses including freezing is a key challenge to agriculture in the face of an unpredictable climate. Cold acclimation allows plants to increase their freezing tolerance through a program of transcriptional and metabolic alterations in response to cool conditions before the onset of winter. The interaction between light and cold acclimation has previously been studied, with light appearing to be important for establishing freezing/cold tolerance especially under long day conditions. Specifically, parameters linked to photosynthetic electron transport are affected by light levels during cold acclimation, and elevated light intensities at normal growth temperatures may induce freezing tolerance. Light also influences the expression level of cold-regulated genes, however, the molecular basis of the interaction between light and cold acclimation is poorly understood. We have shown the gene SENSITIVE-TO-FREEZING 10 (SFR10) encodes a chloroplast-located protein that is necessary for full cold acclimation to freezing stress in Arabidopsis and photosynthetic acclimation to high light levels (unpublished data). Homologues exist across a range of monocot and dicot species, making SFR10 a strong candidate for improving crop productivity and stress resilience. This project will use complementary approaches to understand the mechanistic basis of SFR10's effect whilst revealing its molecular evolution and mutations responsible for increased freezing tolerance. The project will begin with a thorough characterisation of SFR10 loss- and gain-of-function Arabidopsis plants for cold-acclimation-induced freezing tolerance, photosynthetic acclimation, productivity and metabolite content under normal and stress conditions as well as examining the localisation of GFP-tagged SFR10 in response to cold and high light. Preliminary examination of the SFR10 protein sequence reveals a potential DNA-binding domain so it is possible SFR10 regulates the expression of other genes. The candidate will seek to identify chloroplast-localised DNA and protein interactors of SFR10 and will analyse and validate existing RNAseq data to identify SFR10-responsive transcripts. Further to this, we will perform a complementary evolutionary analysis of hundreds of SFR10 homologs from a wide range of angiosperms hailing from different climates, available in GenBank, within the framework of phylogenetic analyses for positive selection. This will allow us to pinpoint potential amino acid switches within the SFR10 protein responsible for increased freezing tolerance. SNPs encoding such amino acid switches will be queried empirically by complementing a complete loss of function sfr10 mutant with modified SFR10 sequences and if time allows, by creating CRISPR-Cas modified Brassica napus, and testing them for freezing tolerance and light acclimation.