Preliminary Study Of The High Temperature Sensitive Mutant Hts2

Lateral root is a key component for plant root architecture. It is essential for water and nutrient uptake and supporting the plant as a part of strong root system. By screening mutant library generated from EMS mutagenesis, we found a high temperature sensitive mutant (hts2). The results were summarized as follows:1?At low temperature condition (24?), mutant (hts2) showed no significant difference with wild type. As the temperature increasing, mutant (hts2) becomes shorter and the number of lateral root is gradually reduced. When the temperature is higher than 32 C, mutant (hts2) showed short shoot, short taproot and no lateral root. Methylene blue staining revealed that mutant (hts2) can form normal lateral root primordia at 32?, but cann't outgrowth through the epidermis.2?Under the condition of high temperature (32 C), high concentration of ABA (1 ?M) and PEG (5% & 10%) can partially recover the lateral-root growth in mutant (hts2). At different temperature, the reaction of the mutant and wild type, for other hormones such as NAA, GA,6-BA and JA, is similar.3?At high temperature (32 C), ABA and PEG show additive effect to recover the lateral-root growth in mutant (hts2). Low concentration of ABA (0.4?M) and PEG(2%) treatment at the same time can recover the lateral-root growth in mutant (hts2), and the effect of PEG(10%) can be suppressed by treatment of ABA synthesis inhibitors (0.2mM). The results suggested that recovery of mutant (hts2) by PEG treatment is dependent on ABA signaling pathway.4?The phenotype of mutant hts2 is controlled by single recessive gene. Through the initial mapping, the mutated gene was mapped on chromosome 4, between two molecular markers 83111-2 and S14831K, a 7329 kbp region with 971 annotate genes. We will further narrow down the map region and use deep sequencing to get the target gene.