Hypersensitive reaction and callose formation were two important resistance mechanisms.是什么意思？

Hypersensitive reaction and callose formation were two important resistance mechanisms.

过敏性坏死反应和胼胝质的形成是2个重要的抗锈机制.

hypersensitive

adj. 过敏的，高度灵敏的；

例句
Student teachers were hypersensitive to any criticism of their performance.
实习教师对任何针对他们表现的批评意见都异常敏感。

reaction

n. 反应，反作用力，反动，保守；

例句
When Chappel approached me about the job, my first reaction was of disbelief...
当查普尔为这份工作找我商量时，我的第一反应是不相信。

and

conj. 和，与，而且，于是，然后，因此；

例句
I spend a lot on expensive jewelry and clothing...
我花很多钱购买昂贵的首饰和衣服。

callose

n. 胼胝质，具胝质；

例句
Hypersensitive reaction and callose formation were two important resistance mechanisms.
过敏性坏死反应和胼胝质的形成是2个重要的抗锈机制.

formation

n. 形成，构成，结构，形成物，编队，队形；

例句
The Prime Minister resigned today, clearing the way for the formation of a new government...
首相今天的辞职为新政府的组建扫清了道路。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

two

n. 两个，两个东西，两点钟，一对；adj. 两个的，我

例句
He has been absent from his desk for two weeks...
他已经有两个星期没有坐在办公桌前了。

important

adj. 重要的，权威的，有势力的，有地位的；

例句
The presence or absence of clouds can have an important impact on heat transfer...
有无云层对热量的传递会产生重要的影响。

resistance

n. 抵抗，阻力，抗力，电阻；

例句
...too much resistance to the displacement of your reason by your emotions.
有太多阻力使你无法用情感代替理智

mechanisms

n. 机械( mechanism的名词复数 )，机械装置，[生物学] 机制，机械作用；

例句
Plants have different mechanisms of dispersal for their spores.
植物传播孢子的方法各不相同。