Casto Anna L, McKinley Brian A, Yu Ka Man Jasmine, Rooney William L, Mullet John E
Department of Biochemistry and Biophysics Texas A&M University College Station Texas.
Molecular and Environmental Plant Sciences Graduate Program Texas A&M University College Station Texas.
Plant Direct. 2018 Nov 12;2(11):e00085. doi: 10.1002/pld3.85. eCollection 2018 Nov.
is a drought-resilient C4 grass used for production of grain, forage, sugar, and biomass. Sorghum genotypes capable of accumulating high levels of stem sucrose have solid stems that contain low levels of aerenchyma. The -locus on SBI06 modulates the extent of aerenchyma formation in sorghum stems and leaf midribs. A QTL aligned with this locus was identified and fine-mapped in populations derived from BTx623IS320c, BTx623R07007, and BTx623*Standard broomcorn. Analysis of coding polymorphisms in the fine-mapped -locus showed that genotypes that accumulate low levels of aerenchyma encode a truncated NAC transcription factor (Sobic.006G147400, ), whereas parental lines that accumulate higher levels of stem aerenchyma encode full-length NAC TFs (). During vegetative stem development, aerenchyma levels are low in nonelongated stem internodes, internode growing zones, and nodes. Aerenchyma levels increase in recently elongated internodes starting at the top of the internode near the center of the stem. was expressed at low levels in nonelongated internodes and internode growing zones and at higher levels in regions of stem internodes that form aerenchyma. , a gene encoding a cysteine protease involved in programmed cell death, was induced in genotypes in parallel with aerenchyma formation in sorghum stems but not in genotypes. Several sweet sorghum genotypes encode the recessive allele and have low levels of stem aerenchyma. Based on these results, we propose that is the -gene identified by Hilton (1916) and that allelic variation in modulates the extent of aerenchyma formation in sorghum stems.
是一种具有抗旱能力的C4禾本科植物，用于生产谷物、饲料、糖和生物质。能够积累高水平茎蔗糖的高粱基因型具有坚实的茎，其中含有低水平的通气组织。SBI06上的-locus调节高粱茎和叶中脉通气组织形成的程度。在源自BTx623IS320c、BTx623R07007和BTx623*标准帚用高粱的群体中鉴定并精细定位了与该位点对齐的一个QTL。对精细定位的-locus中的编码多态性分析表明，积累低水平通气组织的基因型编码一个截短的NAC转录因子（Sobic.006G147400， ），而积累较高水平茎通气组织的亲本系编码全长NAC转录因子（ ）。在营养茎发育过程中，未伸长的茎节间、节间生长区和节中的通气组织水平较低。通气组织水平在最近从茎中心附近的节顶部开始伸长的节间中增加。 在未伸长的节间和节间生长区中低水平表达，在形成通气组织的茎节间区域中高水平表达。 ，一个参与程序性细胞死亡的半胱氨酸蛋白酶编码基因，在高粱茎中与通气组织形成同时在 基因型中被诱导，但在 基因型中未被诱导。几种甜高粱基因型编码隐性等位基因且茎通气组织水平较低。基于这些结果，我们提出 是希尔顿（1916年）鉴定的 -基因，并且 中的等位基因变异调节高粱茎中通气组织形成的程度。
