蔗糖磷酸合成酶（SPS）是蔗糖合成途径中的限速酶，与磷酸蔗糖磷酸酶（SPP）形成复合体共同催化合成蔗糖，在植物生长发育过程中提供能量并在果实品质提升方面发挥着重要作用。目前，关于苹果SPS基因家族的进化模式及系统性分析的研究较少。本研究从苹果基因组GDDH13 v1.1中鉴定了7个MdSPS基因和4个MdSPP基因，并分析了其基因结构、基因启动子顺式元件、蛋白保守基序、亚细胞定位和生理生化特性。染色体定位和基因组复制分析表明，全基因组复制（WGD）和片段复制是MdSPS基因家族进化的主要方式，MdSPS基因对的Ka/Ks比值分析指出该家族成员在驯化过程中经历了较强的纯化选择。根据系统发育关系将SPS基因划分为3个亚家族，并观察到基因亚家族间古老的基因复制事件和差异显著的进化速率。此外，根据‘金冠’、‘富士’、‘秦冠’和‘蜜脆’四个苹果品种果实发育过程中可溶性糖含量与SPS家族基因表达水平的相关性，鉴定了一个蔗糖积累相关的关键基因MdSPSA2.3。随后通过病毒诱导MdSPSA2.3基因沉默证实了该基因在苹果果实蔗糖积累中的重要功能。本研究为更好地阐明MdSPS基因在苹果果实发育过程中的生物学功能奠定了理论基础。

生长素（吲哚-3-乙酸，IAA）对调节植物碳水化合物水平和生长具有较大的影响，但是它调节植物体内糖分水平的机制却很少受到关注。本研究中，我们发现外源IAA主要通过调节MdSUSY1、MdFRK2、MdHxK1和MdSDH2的转录水平进而改变茎尖中果糖（Fru）、葡萄糖（Glc）和蔗糖（Suc）浓度。此外，我们利用五年生的“Royal Gala”苹果树进一步验证这些基因在调控库强方面的主要作用。结果表明，MdSUSY1、MdFRK2、MdHxK1/3和MdSDH2可能是库强调节的主要贡献基因。综上所述，这些结果为碳水化合物代谢机制的调控提供了新的视角，这将有助于调节库强和产量。

己糖激酶（HXK）是糖酵解途径中第一个不可逆的催化酶，不仅为植物的生长和发育提供能量，而且还作为响应环境变化的信号分子。但是，HXK基因家族在苹果中的进化模式仍然未知。本研究中，在苹果（Malus×domestica）基因组GDDH13 v1.1中共鉴定出9个HXKs基因，分析了MdHXKs基因的生理和生化特性，外显子-内含子结构，保守基序和顺式元件，亚细胞定位预测结果表明MdHXKs基因主要分布在线粒体、细胞质和细胞核中。基因复制结果显示，全基因组复制（WGD）和片段复制在MdHXKs基因家族扩展中起着至关重要的作用。成对MdHXKs基因的ω值表明，该家族在苹果驯化过程中经历了强烈的纯化选择。此外，对五个亚家族进行了分类，并根据系统进化树分析确定了最近和最老的重复事件，并评估了不同HXKs亚家族之间的进化速率。此外，MdHXKs基因在四个源/库组织和五个苹果果实发育不同阶段的表达模式表明，MdHXKs基因在苹果果实发育和糖积累中起着至关重要的作用。本研究为今后阐明苹果果实发育过程中MdHXKs基因的生物学功能提供了理论基础。

Soil alkalinity is a major factor that restricts the growth of apple roots. To analyze the response of apple roots to alkali stress, the root structure and endogenous hormones of two apple rootstocks, Malus prunifolia (alkali-tolerant) and Malus hupehensis (alkali-sensitive), were compared. To understand alkali tolerance of M. prunifolia at the molecular level, transcriptome analysis was performed. When plants were cultured in alkaline conditions for 15 d, the root growth of M. hupehensis with weak alkali tolerance decreased significantly. Analysis of endogenous hormone levels showed that the concentrations of indole-3-acetic acid (IAA) and zeatin riboside (ZR) in M. hupehensis under alkali stress were lower than those in the control. However, the trend for IAA and ZR in M. prunifolia was the opposite. The concentration of abscisic acid (ABA) in the roots of the two apple rootstocks under alkali stress increased, but the concentration of ABA in the roots of M. prunifolia was higher than that in M. hupehensis. The expression of IAA-related genes ARF5, GH3.6, SAUR36, and SAUR32 and the Cytokinin (CTK)-related gene IPT5 in M. prunifolia was higher than those in the control, but the expression of these genes in M. hupehensis was lower than those in the control. The expression of ABA-related genes CIPK1 and AHK1 increased in the two apple rootstocks under alkali stress, but the expression of CIPK1 and AHK1 in M. prunifolia was higher than in M. hupehensis. These results demonstrated that under alkali stress, the increase of IAA, ZR, and ABA in roots and the increase of the expression of related genes promoted the growth of roots and improved the alkali tolerance of apple rootstocks.

Sucrose synthases (SUS) are a family of enzymes that play pivotal roles in carbon partitioning, sink strength and plant development.  A total of 11 SUS genes have been identified in the genome of Malus domestica (MdSUSs), and phylogenetic analysis revealed that the MdSUS genes were divided into three groups, named as SUS I, SUS II and SUS III, respectively.  The SUS I and SUS III groups included four homologs each, whereas the SUS II group contained three homologs.  SUS genes in the same group showed similar structural characteristics, such as exon number, size and length distribution.  After assessing four different tissues, MdSUS1s and MdSUS2.1 showed the highest expression in fruit, whereas MdSUS2.2/2.3 and MdSUS3s exhibit the highest expression in shoot tips.  Most MdSUSs showed decreased expression during fruit development, similar to SUS enzyme activity, but both MdSUS2.1 and MdSUS1.4 displayed opposite expression profiles.  These results suggest that different MdSUS genes might play distinct roles in the sink-source sugar cycle and sugar utilization in apple sink tissues.

The objective of this study was to characterize yellow (stripe) rust resistance gene(s) in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in field. Seedlings of wheat cultivars were inoculated with 25 differential isolates of Puccinia striiformis from foreign and home to postulate resistance genes to yellow rust, and then validated by pedigree. There were 10 probable resistance genes characterized in these cultivars, in which, Yr9 was most commonly postulated to be present in thirteen cultivars. Yr21, the second, was present in four cultivars. Yr8, the third, were present in three cultivars. Yr6, Yr17 and Yr26, the fourth, was present in two cultivars respectively. The other gene(s) such as, Yr2+YrA, Yr7 and Yr27, were only present in single cultivar(s); unknown gene(s) or gene(s) combination(s) were present in 22 cultivars. One cultivar (Yunmai 42) had no resistance gene tested in this study. Cultivars such as Yunmai 52, Mian 1971-98, Kunmai 4, and Yunmai 56 carried effective genes and can be popularized mainly; Yr9 should be planted with other Yr genes. In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust. Yunmai 42 should be reduced to avoid rust breakout. Unknown gene cultivars should be utilized and be researched deeply.